Fritz at Champaign Cycle is a great guy. He helped me with some highly custom stuff for riding with one leg a while back. Then he wouldn't take any money for it. I brought them pizza at least and I refer all my friends there.

There are more professional places in the Chicago area, but there aren't any nicer people.

Bruce @ Bikeworks is a character and has helped me find some rare and used stuff on occasion. Do they still have the huge snake in the showroom?