Why does everyone always list Liberty in easy Vai stuff to play? I still find those fast runups etc really hard, and haven't mastered them yet at all. Yet I can play stuff like Dyin Day, Sisters and The Crying Machine and they don't come up as often (yes I know someone mentioned Dyin Day in this thread, its just an example).
Play Satch Boogie if you want to wow, or Sisters if you want something fairly easy and nice. Good thing about the Boogie is that it's pretty loose, so you can improv around instead of playing it exactly note for note.
Always With Me...is a good one too. Surfing With The Alien isn't too hard either.
Pull off the Attitude Song and I'm sure your fellow students will respect you for months to come

. You'd be hard pushed to learn it in 2 weeks though.
I'd go with Satch Boogie.