Well I supposed that would happen, handcoding a database in c# is like writing a parser in perl. lol the good developer loves coding everything, but the great developer is the lazy one borrowing everywhere. If u go the Microsoft way, IIS has everything u need easily and free but it is a huge monster; Firebird SQL is another option, its lightweight and fast, open source, and its documentation and guides are top quality. One way or another, dont worry because driving something is always easier faster than building it.
Once server side is rolling, the ideal dream is packaging the client as a prx module inside ps3 itself using psl1ght sdk. But before running, we have to walk some. Personally, i apply SCRUM (agile methodology with incremental prototypes) as much as i can. Mind u will manage human resources testing for u, knowing how will make u happy.
Btw take a look at how map and multimap containers work, since u want the best performance u can afford while searching and indexing until server does that for u, and those are always ready to use. Also dont feel shy but free to post on my profile anytime, or any other method u rather, i really want to help make this happen.