I had a 2" 64, with a factory bobbed/DAO hammer. Great carry gun. It may be considered blasphemous around here, but I actually preferred carrying it to the 3" 65 I also had at the time.

Don't think I've ever seen a 2" 67, but the adjustable sight guns were never really an interest of mine.

If you really want rare, try finding a 2.5" Model 10. IIRC, they were made for the FBI before the 3" 13 was issued. I think there are a few of them floating around out there.