Client Site Setup

I want to set up a template where clients can order their site (via WHMCS) and then goes to a program where they enter their core information e.g. about us, products, contact etc and it then gets populated to a template of their choice. This would be similar to the ‘create initial webpage’ feature on VM, but allows the user to add the information.

Is anyone aware of a script that could do that, or at least allow login when they first go to their domain to enable that?