I have recently found two bikes at yard sales. One is a Fuji Dynasty 12 the other is a Centurion Cavaletto. I want to build one of them up as a fixed gear--this will be my first build. Unfortunately, neither are ridable right now. Any thoughts as to which is a better choice (other than weight)? From the research I've done, neither bike is special. Should I consider selling both to try to get a better frame?