You might also tool around www.roadbikereview.com. There are lots of threads--too many really--on custom building and builders, frame materials, what to expect from the process, finish, fitting, price, wait time, etc. From what I can tell, lots of builders have their own unofficial fanclub, but a number of names come up more consistently than others as being very good, both in terms of their final product and customer service, including the builder that did SadieKate's latest bike (I'd love to see pics by the way SK). I, personally, would love to go the route that SK took, i.e., going to the builder's shop for a fitting. That would be a HUGE selling point for me.

Incidentally, Don Walker just opened a shop about 8 miles from where I live.

Good look and have fun with it. I'm green with envy!