I scour CL constantly anyway...I'm just not entirely sure what I should be looking for. There seem to be a lot of frames that work in most ways, but not all. I like the idea of resizing an older Volpe or Miyata 1000. I need to look into the the Trek 520s. I also like the idea of a Miyata cross...maybe the triple cross.
The tricky part seems to be finding a horizontal top tube bike with half fork braze ons and the right fender/tire clearance (essentially mtn sizing). The MTBs don't work because almost all of them have vertical drops and/or won;t take 700cs.