Awesome replies, gang. Thanks for all the insight.
After reading all these thoughts, I've given it some thought myself. The thing is, I don't want an M. If I wanted an M, I'd save up and buy an M, or a R2M. I love my R and I can't imagine using an M or R2M for anything more than additional lenses. The impetus behind the Barnack is to work with equipment that will be basic but beautiful. I also would appreciate the huge rangefinder - Even with my young, spry eyes, I often have trouble with the small viewfinder on my R - Framing is less important to me, although I'm interested in experiencing the split set-up as much as the cut-and-load. My concern about anything non-Leica is the inevitable servicing. I've got a great guy here in L.A., but I can't imagine him working on anything non-modern or non-Leica.
Like an above poster, tyrone.s, I'm doing this as a "purity" kick - This is about broadening a horizon, making my brain work a little harder and buying into a pretty significant piece of history. I'd love to make this a camera I could use everyday, and there seem to be plenty of folks who rock Barnacks regularly, but I'm well-award that there's going to be a significant investment of time and learning-curve to get there. I guess that's why I'm trying to do my best picking out the actual equipment - I'd like to at least know my camera's in working order, even if I'm not quite yet.
So is the general consensus that if I don't mind the spacing of the viewfinder and rangefinder, there's no reason to avoid a III/IIIA or even a II? My only concern about those was the brightness. If that's not a concern, I'll broaden my search. I don't mind about the die-cast body since that's rarely anything but cosmetically displeasing.
I'm intrigued by Youxin - A little searching and Googling and he seems to be the guy everyone turns to. What's the best way to approach him with a request for a solid IIIC?
Thanks again for the warm welcome, happy Dad Day to the dads here and looking forward to more insight and education.
N.