Matt: I agree about the weight relationships. That is partly why I am considering a Beseler. I own both Beseler 45s and an Omega D5, so I'm familiar with the breeds. The thing that attracts me about the Beseler 45M is the motorized lift! I've gotten really spoiled by that - but it's not necessary. The crank on a 23C would do just fine.
It's the sturdiness of the girders on the Beselers that I am after. Plus, if I can do it right, the horizontal projection ability of the Beselers will allow me to turn the camera back level and use it like a camera stand. (Although a tripod works, too.) And I agree with Konical that it won't be a major engineering challenge with my skill level.
Yes, I could use mirror lock up, too. My D5 is like a big tuning fork. When I had it set up and was using it, I had the top of the column braced to the wall. I don't want to have to do that with a copy stand set-up.
23Cs come up on the local craigslist periodically. the problem is usually that the owner thinks they're still worth $600 ... Like I said: patience!