Custom Install Script?

Hey guys, so im making a site where a user can pretty much sign up, and it will setup a wordpress install for them on my server, with a subdomain, I know how to make the mysqldb/user create and assign to each other easily.

But how can I make my own installer for wordpress? I poked around on install.php, and its honestly pretty damn confusing, lol… Do you guys have any type of tutorial?

This is almost like fantastico, in a way…