If you plan to shoot bigger, use a tripod (mostly) and you want to shoot studio/portrait/wedding I would strongly suggest the 67II. Brighter viewfinder will help with when you have focus and compose quickly (some wedding scenarios).
Keep in mind if you do get an older 67 it may need to have the foam replaced as well as a general CLA (clean, lubricate and adjustments), which will cost a few hundred (in the USA at least). Why not instead place that money towards a 67II. You mentioned that you like to operate in manual mode, so you can skip the AE finder and go for the less expensive non metered finder. Just some thoughts.
Another option is to get the 645N and get the 67 lens to 645 body adapter and start off with some 6x7 lenses, eventually getting a 6x7 body. You will already have 6x7 lenses and you will have two formats to work with.
Originally posted by netrex I plan to print bigger than that. The two sets I have found that is a 645N and a 67. How is the 67 (not 6x7 or 67II) compared to the 645N? I don't mean the size of the exposure of course, but usability if one doesn't need automatics. I do plan to use it as a studio/portrait/wedding etc. camera a bit as well.
I'd like to shoot hand held as well as on a tripod, but I do mostly use a tripod. I got the K10D and the Z-1p for hand held if it is needed.