I would suggest looking for a complete older bike. I went to the older LBS in my area that sells used bikes. Ask to dig around in the back and tell them what you are doing. Guys in those shops enjoy a good project and should advise you. If they do then give them your buisness, they deserve it. The reason I suggested a complete bike is because you will have almost everything you need and it will all fit. Then find/build a track rear wheel and viola!

There are a lot of old bike boom bikes ( 70's-early 90's) floating around with great comps. Always better to recycle a cycle I say.

Good hunting.