I've built a sort of 'software as a service' website package for a specific industry. What I am looking to do is create a payment gateway that allows users to subscribe-- and once the subscription is active, it would auto-provision a web hosting plan for them (a shared account on a server, probably in a chroot'd environment so each user would be insulated from others). Ideally it would auto-install a CMS as well.

Tons of web hosts provide a simple reseller plan where I could manually create all the users' hosting accounts-- but so far none that I've found allow you to do this via API.

Is there a way to do this short of writing custom shell scripts on something like an EC2 platform? I'd prefer to leave all the server maintenance in the hands of dedicated support staff rather than having to manually handle updates, backups, etc.

Thanks for any tips.