Good for you!
It sounds like you've got the chedder to spare, and you've taken the best step to ensure bike-handleing success- The only thing now is to get the wheel!
I say "wheel" singular because if I were you, I'd keep that Velocity, make sure it's nice and true before heading to the race (get it done about 3 weeks before), and then buy a HED3, which I think some of the other people commented on. Since you have the money, don't buy one of the blemished or slightly out of true ones- get a good one.
Trust me on this one, you can't go wrong with a HED3 rear. The wheel is strong, super stable, and proven. It's also versatile in every race situation...no one can say it's not good for hills, wind, flats, etc etc...and the 3 spoke is more aero than multi-spoke, and since time is a factor...
...and besides, it looks cooler!
Good luck!
Rob
http://www.reathcon.com