Take a field trip out to Zaborski Emporium in Kingston, NY. It's equal parts architectural salvage and vintage/antique housewares, and HUGE.

Also, if you're looking for specific things and don't mind waiting, the guys at Deconstruction Works in VT come across all sorts of random stuff in their projects, and post them on their FB page (or you can call Erich and let him know what you're looking for). They don't have a store, so no random browsing.