I'm interested in building up a fixed gear bike. My problem is that I'm 5' tall and currently ride a Trek 43 cm WSD with 650cm wheels, which is a little too small, but I didn't have many options when I bought it. I've been scouting around for a small used frame with horizontal dropouts, but no luck so far. Since I've never even seen a fixed gear bike small enough for me to ride, it would be a real leap of faith to have one custom made. Any suggestions?