Let the end user create their own site with templates

not sure if this is the right place to ask this question so sorry it's not.

I'm looking to build a site where a new user can build a single page website by simply using a GUI to pick a template, copy and paste some text, maybe add a logo and a photograph and then click publish. They wouldn't need all the fancy back end stuff, no blogging, no plugins, just a simple one page cut, paste, play.

Any ideas gratefully received!

Ian.