If cost is a factor, I would get a Campy Centaur or Veloce aluminum compact. The performance will be similar to the carbon and will only weigh about 65g more and you get to stay Campy.
If you really want carbon, the Centaur compact carbon is going to be getting cheap as well with the new Campy stuff coming out for 2007-and the Centaur compact carbon is 65gm lighter than the Prorace. I have seen them on eBay buy it now for as little as $259 USD.
Both these options let you keep the BB.