Omega Seamaster
If all the money's for a watch, go with that. It's a great watch, looks the part (not too flash, but stands out) and people who know watches will assume you have some class if they see you with one of those on your wrist.
If not, get a cheap(ish) Casio and get the bint to buy you a Bose X headset with the remainder of the wonga instead...
I've seen a lot of the GA fraternity wearing those "Torgeon(?!)" things, and they seem quite popular.