ChatGPT answers, unedited

For a small web-design agency, I’d pick Cloudways first if your priority is minimizing infrastructure work while keeping client sites reasonably separated and billing clients easily.

My shortlist

🥇 My recommendation: Cloudways

cloudways.com is unusually well suited to your use case because its agency tooling is built around managing multiple client projects.

You can put multiple client applications on servers, move a server to a client's own account if necessary, and give team members granular permissions. Cloudways Cloudways Help Center

More importantly, Cloudways has a dedicated Client Billing product. It supports recurring billing, automated invoices, client/service management, and Stripe payment integration. Cloudways Help Center Cloudways

That means you could structure your agency roughly like:

Client A → Site A → hosting + maintenance → $X/month
Client B → Site B → hosting + maintenance → $Y/month
Client C → Site C → hosting + maintenance → $Z/month

without building your own provisioning/billing system.

The downside is that Cloudways isn't really a raw VPS-management platform. You're paying for managed infrastructure and convenience rather than getting maximum control over the underlying VPS.

🥈 If isolation is the #1 priority: Plesk + VPS + WHMCS

If by "isolation" you mean I want every client to have their own hosting account/resources and I don't want one client's site management to bleed into another, I'd look seriously at Plesk + WHMCS.

plesk.com supports separate hosting subscriptions and can integrate with billing systems such as WHMCS, HostBill, Blesta, and ClientExec. Plesk itself doesn't include a billing system. Plesk

Then use whmcs.com for:

• recurring subscriptions
• automated invoices
• payment collection
• provisioning/suspension
• client accounts
• hosting packages
• domain/SSL sales
• client self-service

WHMCS specifically positions itself for agencies and hosting providers and integrates with Plesk. WHMCS Plesk Documentation

This is probably the better long-term architecture if hosting is becoming a significant revenue stream rather than just an add-on to your web-design business.

🥉 If you want to build your own hosting platform

A more powerful but considerably more technical setup would be:

Vultr → Virtualizor → WHMCS

vultr.com provides VPS infrastructure, while Virtualizor handles VPS provisioning and WHMCS handles the commercial side.

WHMCS's Virtualizor integration can automatically create, suspend, terminate, and manage VPSs, including automated actions for nonpayment. WHMCS Documentation WHMCS Apps

Vultr's current organization/IAM system also provides hard boundaries between organizations for resources, users, permissions, and billing. Vultr Docs Vultr Docs

That's attractive if you eventually want to sell "managed VPS hosting" rather than simply host websites for your design clients.

What I'd do in your shoes

Under ~20–30 client sites: Cloudways.

30–100+ sites and hosting becoming a major recurring-revenue product: Plesk + VPS + WHMCS.

Want to become a genuine hosting provider/reseller: Vultr/another VPS provider + Virtualizor + WHMCS.

One important distinction: if by "site isolation" you mean protection against one compromised WordPress site attacking another, tell me that. I'd recommend a somewhat different architecture—particularly whether you should use one VPS per client, one VPS per group of clients, or isolated containers/accounts on shared VPS infrastructure.

For a small web-design agency, I’d optimize for client/site isolation + easy provisioning + recurring billing, rather than simply picking the cheapest VPS.

My top choice: VPS + Plesk + WHMCS

I’d use a VPS from a mainstream provider and put Plesk on it, with WHMCS handling billing.

Why this combination fits an agency:

• Isolation: Plesk gives each client their own customer/subscription environment, with separately managed websites, databases, mail, permissions and resource limits. docs.plesk.com
• Billing: Plesk integrates with WHMCS, Blesta, HostBill, BILLmanager and others. support.plesk.com
• Automation: WHMCS can handle recurring invoices, payments, provisioning, suspensions and client management. www.whmcs.com
• Agency-friendly: Plesk specifically positions its platform around agencies managing multiple client servers, subscriptions and services. www.plesk.com
• Room to grow: You can start with one VPS and eventually spread clients across multiple servers without completely changing your management model.

A particularly nice setup is:

VPS → Plesk → individual client subscriptions → WHMCS → Stripe/PayPal

So when Client A stops paying, WHMCS can suspend their hosting without affecting Client B.

If you want more VPS-level isolation

If by "site isolation" you mean each client gets an actual VM, rather than separate hosting accounts on one VPS, I'd look at SolusVM + WHMCS.

SolusVM is specifically designed for VPS provisioning and supports automatic creation, suspension and deletion of VPS instances, with WHMCS integration. www.plesk.com

That's more appropriate if you're selling things like:

"Your own dedicated 2-vCPU / 4-GB VPS"

rather than:

"Managed website hosting for $X/month."

Another good architecture: DigitalOcean + Plesk

DigitalOcean + Plesk + WHMCS is attractive if you want straightforward infrastructure and API automation. DigitalOcean even offers a WHMCS/Plesk deployment that can be provisioned through its API. docs.digitalocean.com

WHMCS also has provisioning modules for providers including Hetzner, DigitalOcean/Linode-type infrastructure, OVHcloud, Proxmox, etc. marketplace.whmcs.com

What I'd choose for your agency

My default recommendation: start with Plesk + WHMCS on a managed VPS. It gives you the cleanest separation between your agency's infrastructure and each client's account without making you become a full-time hosting administrator.

If you tell me roughly how many sites you host now (e.g. 10, 50, 200), WordPress vs custom apps, and what you want to charge clients/month, I can narrow this down to 2–3 specific VPS providers and a concrete architecture/cost estimate.

For a small web-design agency, I’d optimize for per-client isolation + low operational overhead + automated recurring billing, rather than buying raw VPSs and manually managing each site.

My top pick: Plesk + Blesta

Plesk is probably the best fit for your actual workflow.

• Isolation: Give each client/site its own subscription/account, rather than putting everyone into one Linux user. Plesk is explicitly designed around separate hosting users, resellers, and service-provider accounts. www.plesk.com
• Agency-friendly management: You can manage multiple websites, PHP versions, databases, SSL, backups, staging, etc. from one panel.
• Billing: Pair it with Blesta. Blesta supports Plesk provisioning and can automatically create/suspend services based on billing status. www.blesta.comwww.blesta.com
• Payments: Blesta supports 30+ payment gateways, including Stripe and PayPal. www.blesta.comwww.blesta.com
• Client portal: Clients can have their own login for invoices, services and support without needing access to your infrastructure.

A sensible architecture would be:

VPS → Plesk → one subscription per client → Blesta → Stripe

That gives you a pretty clean "client stops paying → hosting gets suspended" workflow.

If you want maximum automation

I'd look at VirtFusion + Blesta instead. Blesta has a native VirtFusion integration. www.plesk.comwww.blesta.com

That's more attractive if your business is evolving toward selling actual VPS instances rather than simply hosting client websites.

For example:

Client A → VPS/account A
Client B → VPS/account B
Client C → VPS/account C

This gives stronger infrastructure-level isolation, but it's also more infrastructure to operate.

What I'd choose by agency size

WHMCS is also a very solid choice, particularly if you want the biggest hosting-industry ecosystem. Its cPanel integration, for example, handles automated provisioning, upgrades/downgrades, suspensions and terminations. apps.whmcs.com

But for a small web agency, I'd lean Plesk + Blesta because it keeps the stack relatively straightforward while still giving you proper client separation and recurring billing.

One important distinction: don't confuse website/account isolation with VPS isolation. If you put 30 clients on one VPS, Plesk can isolate their accounts reasonably well, but a compromised kernel or VPS affects everyone. If your contracts require strong tenant isolation, use one VPS/container/VM per client or per trust group instead.

If you tell me roughly how many sites you host now (e.g. 10/50/200), whether they're mostly WordPress, and what you want to charge per month, I can recommend a specific VPS + control-panel + billing stack and estimate the monthly cost.

For a small web design agency, I’d optimize for per-client isolation + automated billing/provisioning, rather than simply picking the cheapest VPS.

My recommendation: VPS + VirtFusion/Virtualizor + Blesta

Best overall setup:
VPS provider → virtualization/control layer → one isolated environment per client → Blesta for billing

Why I like this for an agency:

• Isolation: each client can get their own VPS/container/account rather than sharing one filesystem.
• Easy offboarding: suspend/delete one client's environment without touching anyone else's sites.
• Automated provisioning: a paid invoice/order can trigger creation of the environment.
• Recurring billing: Blesta handles invoices, recurring payments, taxes, dunning, etc. It currently advertises 30+ payment gateways and 40+ provisioning integrations. www.blesta.comwww.blesta.com
• Agency-friendly pricing: Blesta's current published plans don't scale with your number of clients in the same way WHMCS does. www.blesta.comwww.blesta.com

For VPS virtualization specifically, Virtualizor + WHMCS is a very mature alternative. Virtualizor has an official WHMCS module that can automatically create, suspend, and delete VPSs based on orders. www.virtualizor.com

What I'd choose by agency size

One important distinction: don't give every client a whole VPS unless you need to. For typical brochure/WordPress sites, individual hosting accounts with resource limits are substantially cheaper and easier to manage. If a client needs root access, unusual software, or strong noisy-neighbor isolation, then give them their own VPS.

The stack I'd build today

Budget-conscious agency:

Hetzner/Vultr/etc. VPS → DirectAdmin → isolated client accounts → Blesta + Stripe

Higher-isolation managed hosting:

VPS cluster → VirtFusion/Virtualizor → one VPS per client → Blesta/WHMCS → Stripe

Blesta is particularly interesting for you because it combines billing, client management, provisioning and support rather than requiring you to bolt together several SaaS products. www.blesta.com

If you tell me roughly how many sites you host now (e.g. 10, 50, 200), whether they're mostly WordPress, and whether clients need their own hosting login, I can recommend a concrete stack—including VPS provider, control panel, isolation model, and approximate monthly cost.

For a small web design agency, I’d prioritize (1) hard client isolation, (2) easy provisioning, (3) recurring billing automation, and (4) low ops overhead. The “best” choice depends on whether you want to become a hosting provider or just resell managed hosting.

Here are the strongest options:

www.webhostwatch.comlisticler.com

My recommendation for a typical small web design agency

Option A — You want to sell “website care + hosting” packages

• VPS provider: DigitalOcean, Hetzner, Vultr, etc.
• Control layer: Enhance or Plesk
• Billing: WHMCS or Stripe subscriptions
• Backups: automated off-server snapshots
• DNS: Cloudflare

This gives you a repeatable product:

• Client A → isolated account
• Client B → isolated account
• Different resource limits
• Easy suspension/migration when needed

Enhance is particularly interesting for agencies because it is designed around managing many sites across servers rather than just one VPS. www.webhostwatch.com

Option B — You mainly build WordPress sites

I would look at:

• GridPane
• RunCloud
• SpinupWP

They are less “hosting reseller” and more “agency operations platforms”: staging, cloning, updates, backups, and managing many WordPress installs. www.webhostwatch.comlisticler.com

Option C — Cheapest DIY stack

• VPS
• CloudPanel or HestiaCP
• Stripe billing manually
• Client records in your CRM

Works, but you become the sysadmin. Free panels can reduce licensing costs but don’t remove the operational burden of backups, patching, monitoring, and support. www.ynvar.com

Billing stack I’d pair with it

For a small agency:

• Stripe Billing → simplest recurring hosting charges
• WHMCS → if you want automated hosting accounts, invoices, provisioning, client portals
• Bonsai / Harvest / your existing CRM → if hosting is just an add-on line item

My shortlist:

1. Enhance + WHMCS + VPS → best “agency becomes hosting provider” setup
2. Plesk + Stripe → easiest professional setup
3. GridPane/RunCloud + Stripe → best for WordPress-focused agencies

If you tell me roughly how many client sites you host now (5, 25, 100+) and whether they’re mostly WordPress, I can narrow this to a specific stack.

For a small web-design agency hosting client sites on VPSs, I’d lean toward Virtualizor + WHMCS.

My pick: Virtualizor + WHMCS

Virtualizor gives you a VPS-management layer on top of your own servers, while WHMCS handles clients, invoices, subscriptions, and provisioning.

Why it fits your use case:

• Strong isolation: Give each client their own VPS/VM rather than putting everything into one shared server.
• Automated provisioning: WHMCS can automatically create, suspend, terminate, and change VPS packages through Virtualizor. www.virtualizor.com
• Client self-service: Clients can manage their VPS from the WHMCS client area, including access to the Virtualizor panel via SSO. apps.whmcs.com
• Billing automation: WHMCS can handle recurring billing and automatically suspend/terminate services for nonpayment. apps.whmcs.com
• You can sell different packages: e.g. $49/mo Starter, $89/mo Business, $149/mo WooCommerce, with different CPU/RAM/storage allocations.
• Room to scale: Virtualizor supports clustering and multiple nodes, so you don't have to redesign everything when you go from 5 clients to 50+. apps.whmcs.comwww.virtualizor.comwww.plesk.com

The current Virtualizor WHMCS module was updated July 6, 2026, so the integration is actively maintained. www.virtualizor.com

One important distinction

If by "site isolation" you mean each website gets its own isolated environment, but you don't necessarily want a whole VPS per client, I'd look at Plesk + CloudLinux instead.

Plesk is particularly nice for an agency because you can manage many websites from one VPS and give individual customers controlled access. Plesk also integrates with WHMCS and other billing systems. www.plesk.com

So I'd choose:

For a web-design agency, I'd probably start with Plesk/CloudLinux if your primary product is "managed websites," and Virtualizor if your primary product is "managed VPSs."

If you tell me roughly how many client sites you have now (e.g. 10/50/100), whether each client needs WordPress, and what you want to charge per month, I can recommend the actual stack and VPS architecture I'd use.

For a small web-design agency, I’d separate the decision into VPS provider + server-management panel + billing rather than looking for a single VPS host that does everything.

My top pick: Ploi + a VPS provider

Ploi is probably the best fit if your priority is easy client-site isolation.

• Per-site isolation: Ploi can run every site under its own Linux system user, with separate file permissions and PHP-FPM processes. A compromised client site therefore has much less ability to access other clients' sites. ploi.io
• Client/team permissions: You can restrict users to specific servers and even specific sites, which is useful if you eventually give clients or contractors limited access. ploi.io
• Works with many VPS providers: DigitalOcean, Vultr, Linode, AWS, UpCloud, Scaleway, or essentially any compatible VPS. ploi.io
• API: You can automate site creation, databases, deployments, etc., which is useful for tying your own client onboarding/billing system into hosting. developers.ploi.io
• Cost: Ploi currently starts free for one server/one site; its Basic plan is listed at $10/mo and supports unlimited sites on up to five servers. ploi.io

The catch: Ploi isn't primarily a hosting billing system. If you want clients to subscribe, receive invoices, pay automatically, get suspended for nonpayment, etc., you'll want a billing layer alongside it.

If billing automation is the #1 priority: Virtualizor + WHMCS

Virtualizor + WHMCS is the more "hosting company" approach.

Virtualizor has a WHMCS integration that can automatically create, suspend, terminate and modify VPSs, while WHMCS handles the customer/billing side. It also supports client self-service and SSO. docs.whmcs.com

That's excellent if you're planning to actually resell VPSs, but it's more infrastructure than most small web agencies need if you're simply hosting WordPress/client websites.

Another good option: RunCloud

RunCloud is very attractive for agencies because its web applications are independently permissioned, and you can create separate system users for individual sites. ploi.ioploi.ioploi.ioruncloud.io

Its newer Arch offering goes further with white-label billing, automated provisioning, suspension, and WHMCS integration. runcloud.io

What I'd choose for your agency

My recommendation: start with Ploi + a reputable VPS provider, and give every client site its own system user. Put your agency's existing invoicing/Stripe workflow on top rather than introducing WHMCS unless you're going to have a substantial number of hosting customers.

If you tell me roughly how many client sites you host now (e.g. 10, 30, 100), WordPress vs custom sites, and whether you want clients to log into a portal, I can narrow this down to a specific stack and VPS size.

For a small web design agency, I’d build around Enhance + a VPS provider + WHMCS rather than buying a traditional reseller-hosting package.

My top pick: Enhance + Hetzner + WHMCS

Why this stack fits an agency:

• Client isolation: Enhance gives you separate website/customer environments, hard resource limits, and isolated website containers. You can also move sites between servers as you grow. enhance.com
• One dashboard: You can manage servers, customers and websites centrally rather than maintaining a separate cPanel installation per VPS. enhance.com
• Billing automation: WHMCS can handle recurring invoices, payments, suspensions, provisioning and a client portal. www.whmcs.com
• Agency-friendly scaling: Enhance can run across multiple servers and automatically place/move sites, so you can start with one VPS and add another when you need capacity. enhance.com
• Reasonable licensing model: Enhance advertises $0/server licensing and agency/reseller plans such as 500 websites for $40/month, rather than charging a separate control-panel license for every VPS. enhance.com

For the infrastructure provider, Hetzner is particularly attractive if low VPS cost is a priority. WHMCS's marketplace has modules for automating Hetzner Cloud servers, so you can eventually automate VPS provisioning too. marketplace.whmcs.com

How I'd structure it

Client
   ↓
WHMCS
   ↓
Enhance
   ↓
VPS cluster
 ├── Client A site
 ├── Client B site
 ├── Client C site
 └── Client D site

Each client gets their own hosting account/site, limits and credentials. WHMCS becomes your billing + client portal, while Enhance handles the actual hosting.

Alternatives

One important distinction: Enhance itself isn't the billing system. It handles hosting/server automation; you'll want WHMCS, Blesta, ClientExec, etc. for subscriptions and client billing. Enhance explicitly supports this model. community.enhance.com

If your agency has ~5–50 client sites, I'd personally start with one good VPS, Enhance, and WHMCS rather than putting every client on a separate VPS. You get isolation at the site/account level without multiplying your infrastructure costs.

If you tell me roughly how many sites you host now, WordPress vs. custom sites, and what you want to charge clients per month, I can recommend the exact VPS size and a concrete stack/cost breakdown.

For a small web design agency, I’d recommend a VPS + Plesk/WHMCS, rather than looking for a VPS provider that does everything itself.

My top pick: Plesk + WHMCS

Plesk is particularly well suited to agencies because you can give each client their own hosting subscription/account, with separate users, domains, databases, PHP settings, resource limits, and permissions. Plesk explicitly supports WHMCS for provisioning and billing customer accounts. www.plesk.com

Pair it with WHMCS:

• Client isolation: one Plesk subscription per client/site.
• Automatic provisioning: client pays → hosting account gets created.
• Recurring billing: invoices, automatic payments, overdue suspension, renewals.
• Client portal: clients can see/manage their hosting and billing.
• Usage billing: WHMCS can bill based on things such as bandwidth/disk usage. help.whmcs.com
• Easy scaling: you can eventually spread clients across multiple VPSs without changing the overall billing workflow.

WHMCS also specifically positions itself for agencies that want to bundle hosting/maintenance into recurring subscriptions. www.whmcs.com

If you actually want to sell VPSs

If your clients need their own VPS, rather than simply isolated websites, I'd look at Virtualizor + WHMCS.

Virtualizor provides VPS provisioning and has a WHMCS module capable of automatically creating, suspending, changing, and terminating VPSs. docs.whmcs.com

That gives you an architecture like:

Your VPS infrastructure → Virtualizor → individual client VPSs → WHMCS → billing/client portal

Virtualizor also has its own API and supports billing-system integration, so it's a good choice if you eventually want more automation. www.plesk.comhelp.whmcs.comwww.virtualizor.com

What I'd choose for your agency

For a typical web design agency, I'd start with Plesk + WHMCS. Give each client their own Plesk subscription, put sensible CPU/RAM/storage limits around workloads, and sell hosting as a recurring add-on to your design/maintenance services.

If you tell me roughly how many sites you host now (e.g. 10, 50, 200), whether they're mostly WordPress, and your monthly hosting budget, I can narrow this down to 3 specific VPS providers/configurations and compare cost, isolation, backups, and WHMCS integration.

For a small web design agency, I’d separate the problem into VPS provider + hosting control panel + billing/provisioning. That gives you much better client isolation than simply putting sites on a raw VPS.

My top pick: DigitalOcean + CloudPanel + WHMCS

Why this stack works well:

• DigitalOcean — easy VPS provisioning, strong API, snapshots/backups, and straightforward infrastructure billing. Its Droplet API can create/delete/manage servers programmatically. docs.digitalocean.com
• CloudPanel — free and relatively lightweight. It explicitly supports site-level isolation, so each client's site can have its own system-level environment rather than everything sharing one Unix user. www.cloudpanel.io
• WHMCS — the piece I'd use for your client-facing business layer: recurring invoices, payment collection, client accounts, provisioning, suspension for nonpayment, etc. Its cPanel integration is particularly mature. www.whmcs.com

The architecture would look roughly like:

Client → WHMCS → hosting plan → VPS/CloudPanel → individual client site

That lets you sell something like:

…and have WHMCS handle recurring billing while you manage the actual sites through the panel.

If you want the easiest agency-oriented option

I'd seriously look at RunCloud instead of CloudPanel. Its newer Arch platform specifically offers white-label client billing, automated provisioning, automated suspension, and WHMCS integration. runcloud.io

That's particularly attractive if hosting is becoming a product your agency sells, rather than merely infrastructure for your design clients.

If you want the most traditional hosting business

Go with cPanel/WHM + WHMCS.

It's more expensive and heavier, but the integration is extremely mature: automated account creation, suspension/reactivation, resource reporting, package upgrades, SSO, and billing automation are all supported. www.whmcs.com

What I'd choose

For ~5–50 client websites:
DigitalOcean + CloudPanel + WHMCS

For ~20–200 sites and you want hosting to become a serious revenue stream:
VPS provider + RunCloud/Arch + WHMCS

For a traditional reseller-hosting experience where clients expect cPanel:
VPS + cPanel/WHM + WHMCS

One important distinction: don't give each client their own VPS unless you actually need that level of isolation. For typical WordPress/business sites, multiple isolated site accounts on a well-sized VPS are dramatically more economical. CloudPanel, for example, is explicitly designed to isolate sites on the same server. www.cloudpanel.io

If you tell me roughly how many client sites you host now (and whether they're mostly WordPress), I can recommend a concrete stack—including VPS size, panel, billing system, backups, and an approximate monthly cost per client.

For a small web-design agency, I’d recommend a VPS provider + Plesk + WHMCS, rather than trying to make the VPS provider itself handle your client hosting workflow.

My pick: Hetzner + Plesk + WHMCS

Hetzner for the VPS layer, Plesk for hosting/site management, and WHMCS for billing.

Why this stack fits an agency:

• Client isolation: Plesk gives each client their own subscription/account, with resource and hosting-plan controls. docs.plesk.com
• Easy client management: Plesk has separate administrator, reseller, and customer interfaces, so clients don't need root/server access. docs.plesk.com
• Automated billing: WHMCS handles recurring invoices, payment collection, suspensions, upgrades, etc. www.whmcs.com
• Provisioning automation: WHMCS can automatically create/suspend/terminate hosting accounts through Plesk. www.whmcs.com
• VPS automation: There are current WHMCS modules for Hetzner that can provision/manage VPS instances through the client portal. marketplace.whmcs.com
• Good agency economics: You can put many relatively small client sites on a larger VPS while keeping their accounts logically separated.

How I'd structure it

Hetzner VPS
   │
   ├── Plesk
   │    ├── Client A subscription
   │    ├── Client B subscription
   │    ├── Client C subscription
   │    └── Client D subscription
   │
   └── WHMCS (separate server / WHMCS Cloud)
        ├── Billing
        ├── Client portal
        ├── Automatic provisioning
        ├── Automatic suspension
        └── Recurring subscriptions

I'd actually put WHMCS on its own managed instance rather than on the same Plesk VPS. Plesk specifically warns against installing WHMCS on the same Plesk server that WHMCS is managing. support.plesk.com

One alternative I'd seriously consider

If you value simplicity over lowest VPS cost, use DigitalOcean + Plesk + WHMCS. DigitalOcean has a mature API for creating, destroying, resizing and managing Droplets, and current documentation supports deploying Plesk/cPanel-style hosting software on Droplets. docs.digitalocean.com

I'd choose:

If you're primarily hosting WordPress/PHP sites that you build and maintain for clients, I'd go with Hetzner + Plesk + WHMCS. If you tell me roughly how many client sites you have (e.g. 10, 30, 100) and whether they're mostly WordPress, I can recommend a specific VPS size and a sensible per-client pricing model.

For a small web design agency, I’d optimize for per-client isolation + automated provisioning + recurring billing, rather than simply picking the cheapest VPS.

My top choice: Hetzner + Enhance + WHMCS

Architecture:

• VPS: Hetzner Cloud
• Hosting control/orchestration: Enhance
• Client billing/portal: WHMCS
• Payments: Stripe through WHMCS

Why I like this setup for an agency:

• Enhance is designed around hosting multiple independent websites/accounts, rather than treating everything as one giant VPS account. It also supports multi-server setups, so you can grow from one VPS to several without redesigning your whole hosting operation.
• WHMCS handles recurring invoices, payment collection, client accounts, provisioning and suspensions, and has integrations with major control panels. www.whmcs.com
• Hetzner gives you inexpensive underlying compute, while you retain control over the hosting layer.
• You can sell something like $25–$50/month managed hosting while your infrastructure cost is substantially lower.

If you want the easiest setup

I'd seriously consider RunCloud Arch + Hetzner instead.

RunCloud's current Arch product specifically targets agencies/hosting businesses: it provides a branded client dashboard, automated billing, provisioning, suspension for overdue accounts, and WHMCS integration. It also lets you bring your own infrastructure, including Hetzner. runcloud.io

That makes it particularly attractive if you don't want to become a Linux/server administration company.

My ranking

Linode/Akamai is particularly good if you're planning to automate provisioning yourself: its API can create/manage servers and also expose account/invoice/billing operations. techdocs.akamai.com

What I'd do in your shoes

If you're primarily building WordPress/PHP brochure sites for small-business clients, I'd start with:

Hetzner → Enhance → WHMCS → Stripe

Give each client/site its own hosting account with resource limits, backups, SSL, separate credentials, and ideally separate PHP-FPM/process boundaries. Then WHMCS becomes the thing your clients interact with for invoices and subscriptions.

I would not start by putting every client on a separate VPS. That's expensive and creates unnecessary management overhead. Start with strong per-site/account isolation and move particularly demanding or security-sensitive clients onto their own VPS later.

One important distinction: billing integration can mean either "I want my clients to pay me automatically" or "I want my hosting platform to automatically charge/provision against my VPS provider." The architecture above handles the former; the VPS providers' APIs handle the latter.

If you tell me roughly how many sites you host now (e.g. 10, 50, 200) and whether they're mostly WordPress, I can narrow this down to a specific VPS size and monthly cost model.

For a small web design agency, I’d lean toward DigitalOcean + a hosting/billing layer, rather than looking for a VPS provider that does everything itself.

My pick: DigitalOcean + WHMCS

DigitalOcean is a particularly good fit if you’re comfortable with a little initial setup.

• Client isolation: Put each client/site in its own Droplet, or group related resources into separate DigitalOcean Projects. Projects are explicitly designed for organizing resources around applications and clients. docs.digitalocean.com
• Automation: DigitalOcean has an API for creating/deleting/managing Droplets and other infrastructure, so you can automate provisioning when a client signs up or cancels. docs.digitalocean.com
• Billing integration: Its API exposes invoices, billing history, balances and billing insights. docs.digitalocean.com
• Agency billing: WHMCS is designed specifically around hosting businesses and agencies, with recurring billing, provisioning, suspensions, client portals, payment gateways and APIs. www.whmcs.comwww.whmcs.com

A practical architecture would be:

Client → WHMCS → provisioning automation → DigitalOcean → isolated VPS/site

You could charge, for example, $49–$149/month per managed site, while your actual infrastructure cost stays relatively low. WHMCS handles the customer-facing subscription/invoicing side, while DigitalOcean handles the infrastructure.

If you want maximum simplicity

I'd actually consider one VPS per client rather than putting dozens of client sites on one VPS. It costs more, but makes offboarding, backups, security boundaries, resource problems, migrations and client-specific configurations dramatically easier.

DigitalOcean also has Teams with separate billing/payment information, so you can create organizational separation when appropriate. docs.digitalocean.com

One caveat

If by "site isolation" you mean multiple WordPress sites on the same physical VPS but isolated from each other, I'd choose a control-panel/hosting stack instead—e.g. CloudLinux + cPanel/DirectAdmin + WHMCS. That's a different model from one VM per client.

WHMCS specifically integrates with cPanel, Plesk and DirectAdmin and can automate provisioning, suspension and termination. www.whmcs.comwww.whmcs.com

My ranking for your use case:

If you're starting from scratch, I'd choose DigitalOcean + WHMCS. It gives you a clean path from 5 clients to dozens without having to redesign your billing/provisioning system later.

For a small web design agency, I’d avoid giving each client a raw VPS unless they actually need server-level control. A better setup is usually:

VPS/cloud infrastructure + a hosting control panel + WHMCS for billing/provisioning.

My top pick: Proxmox + WHMCS

If you're comfortable managing servers, Proxmox VE + WHMCS is probably the best long-term setup.

• Client isolation: Give each client their own VM or container. A problem on one client site is much less likely to affect another.
• Resource limits: CPU/RAM/storage can be allocated per client.
• Billing: WHMCS can automate recurring invoices, payments, provisioning, suspension and termination. www.whmcs.commarketplace.whmcs.comwww.whmcs.commarketplace.whmcs.comwww.digitalocean.com
• Automation: WHMCS has a Proxmox provisioning module available in its marketplace. marketplace.whmcs.commarketplace.whmcs.com
• Flexibility: You can move underlying VPS providers later without rebuilding your client-management system.

The downside is that you become the hosting provider: backups, security, OS updates, monitoring, networking, etc. are your responsibility.

If you want less sysadmin work: cPanel/WHM + WHMCS

For a web design agency, this may actually be the sweet spot.

Put one or more VPSs behind cPanel/WHM, create a separate cPanel account for each client, and use WHMCS for billing.

WHMCS supports cPanel provisioning, account suspension/reactivation, usage reporting, password resets, and single sign-on. www.whmcs.com

This gives you:

Client → WHMCS billing portal → cPanel account → client's website

rather than:

Client → entire VPS

That's a much nicer model if you're hosting WordPress/business sites rather than selling VPSs themselves.

If you actually want to sell VPSs: Virtualizor + WHMCS

Virtualizor + WHMCS is the combination I'd look at if each customer should get an actual VPS.

WHMCS's Virtualizor integration supports automated VPS creation, suspension, termination, package changes, usage information and client-side management. apps.whmcs.comwww.whmcs.com

Virtualizor also explicitly supports selling VPSs through reseller/cloud accounts. www.virtualizor.com

Infrastructure provider

For the underlying servers, I'd shortlist:

WHMCS's marketplace currently has provisioning modules for Hetzner, DigitalOcean, Vultr, Proxmox, OVHcloud and others, so you're not locked into one infrastructure provider. marketplace.whmcs.commarketplace.whmcs.com

DigitalOcean itself specifically markets its reseller offering toward developers and agencies, with multiple client Droplets managed under one account. www.digitalocean.com

What I'd do in your shoes

If you're hosting normal client websites, I'd start with:

Hetzner VPS → cPanel/WHM → WHMCS → Stripe

Each client gets:

• their own cPanel account
• their own database/files/email configuration
• resource limits
• separate backups
• separate billing/subscription
• WHMCS client portal
• automatic suspension for nonpayment

Then charge clients something like $20–50/month for managed hosting, depending on what you include, while your infrastructure cost remains relatively low.

If you expect clients to need full root access, Docker environments, custom stacks, or genuinely isolated servers, switch the architecture to Proxmox → individual VMs → WHMCS.

One important point: WHMCS is the billing/provisioning layer, not the isolation layer. The isolation comes from cPanel accounts, containers, or VMs. WHMCS simply automates creating and managing those resources. apps.whmcs.comwww.whmcs.com

If you tell me roughly how many client sites you have (e.g. 10/50/200), whether they're mostly WordPress, and whether clients need email, I can recommend a specific stack and approximate monthly cost.