Pro Sites VS WHMCS MU Provisioning

Hello, I would like to create a business based around free website installations, but charge hosting say ~$10/month. I have noticed there appear to be 2 ways of doing this...either using WHMCS MU Provisioning or using the Pro Sites Plugin. I don't want to have the customer leave my site to register a domain name or to set up nameservers etc. I would like it to be a seemless process...they select a hosting plan, domain name, and pay, it gets registered, the domain is correctly mapped to the server, wordpress mu installation occurs, then propogation aside, they have a new website almost instantly. It appears that with Pro Sites, there is no way to have them register a domain on my if they want their own domain, they have to get it separately. Will WHMCS MU Provisioning allow me to do everything I want? Thanks for the help.