I'm actually working on something like this in my free time for Ubuntu flavors. I've been trying to figure out how to get some funding for it so I can focus on it, but I'm not sure if it's a service I should try to charge users for (automated customization of Ubuntu linux flavor live/installcds).

I figure that once I have a proof-of-concept I can show it to people who might be willing to invest in it so I could afford to host it somewhere and so on.

Right now I'm focusing on package installation / removal, but I plan on adding the ability to put some stuff in your home folder for first user creation, and upload specific configuration files.