Well, I don't know anyone selling their DSLR gear, but go to www.keh.com and check out their used gear. (BTW to mods - if posting an outside market link is a "no-no" than I apologize)

They have a rating system that is actually really accurate on the quality of the piece of gear you're looking at, and their prices are generally pretty good in America.

Otherwise you can try ebay - it creeps me out for good high-end gear, but many people do it.

Good luck - hope that helps-

-Lew ;-)