I am looking to upgrade my trek 7000zx to disc brakes, and I am going to build the wheels. I plan on using Avid bb7 brakes and I am wondering if any one can recommend a good hub-rim combination. I was also wondering if I should go with a 32h 3cross or a 36h 4 cross. I weigh about 190-200 and live in Chicago, so I will not be bombing down any hills soon, but I still want a very strong wheel. Any answers will be greatly appreciated.