Demo creater with theme selector, and payment

am looking for a plugin, or a solution to let users create a demo site, and they will get a uniq link sent on mail to them with login details. They can select from X number of themes during the creation of the demo site, and sample content will allready be imported for them. Also have some fileds like pagename(s), and logo they can upload. After X time they are able to pay for the site, and download the database, and files to their on server.

Also possible to add more themes, plugins, and sample content to the demo creater later. Does anyone know of a plugin, or a solution how to set this up?