These are the practical, real world advice and comments I was hoping for. Thank you! I know certain cameras are better suited to certain things, but info like the variations between the Sinar Fs and other suitable, lighter monos is exactly what I was looking for. And with Rick's rather obvious suggestion of wheels (I didn't actually think a that...dur!), that pretty much takes care of the questions I had about the best way to manage the big camera on shoots - i.e. short treks from the car.
I'm pretty sure that settles the question of what camera to get me started in 8x10. If it all works out well with the BIG MONORAIL and I end up satisfied with 8x10 contact prints only (from an earlier post of mine) - I'll just keep it and get a folder later for the added mobility of the lighter camera. That worked will with 4x5 and I still use both cameras when the situation calls for it.
And BTW - to address the question of medium and materials - I don't now and never expect to do wet plate or anything else like that. I am a straight up B&W film guy only and other than the possibility of some alternative printing processes, intend to stay that way. I used to shoot color 35mm and now I have a little digicam for that on those rare occasions when color is necessary. I figure I can get the rest of my lifetime's worth mastering monochrome photography and have no intention of moving off that path anytime soon. Hopefully that will keep me squarely in the market for materials for the foreseeable future.
Thanks again all, for your input and your experience in helping me make this decision. That's exactly why I come here!