I can think of four categories each for a top gun. One for every fighter (awing, Int, TIE LN, and X wing).

Now how we could go about this could be simple or could be complex. The obvious choice would just have 'duels' where fighter pilots fight each other one on one. Thing with this is that it wouldn't be much fun because:
A. Alot of looping would be done
B. If you have equal pilots in skill the TIE Int would always kill the Xwing and the Awing would always kill whatever it can get behind.
C. Lets face it, if FS winning a DUEL isn't important. Winning many duels (and their by killing alot of bombers/fighters) is important. ALSO FS is about epic grand standing battles, you'd never see a lone TIE take on a lone Xwing... they'd be in packs and probably with a big ship or two throwing in flack too!

The other choice would be organizing a map that is the Battle of Taloraan for all intents and purposes BUUT have every contestant fly in a fighter while we get normal players to fly bombers/capships... then at the end of three or so rounds the average score is taken and multiplied by the average K/D ratio and that would be the winner