If you race, for prize money, and are good at it, then go for the Zipps. IMHO, spending $2000 for a set of daily ridden wheels for the casual rider is a waste. I have a decent set of Shimano 550's for which I paid $230. Search Colorado Cyclist, Performance Bike, Nashbar, and Bicycle Tires. I would paste the links but you know...just delete the spaces in between, add a "www" in front of, and a ".com" behind and you'll have the link.
I think that there are a lot of choices out there.