I designed my second frame to work with either 650b or 700c. Turns out it has really standard dimensions, 68mm BB drop, 73 parallel, 415mm chainstays, so, honestly, pretty much anything in the 25+ year old racing bike category should work, or anything in the sport tourer category...but you might need to buy a new set of brake calipers. FWIW, my bike rides like a dream...pics here http://www.flickr.com/photos/2214371...7626547737510/

Pete