Have you heard of the quadstitch back ?
That company should know what will work and what won't. I checked it out and while it might be good for a still life shooter, it's too bulky and complicated for what I'd like to do.
I remember similar backs from when MF sensors first came out. That and the fact I've been using Autopano made me think I could simply do it with my Technikardan. I most likely will stitch just one horizontal row. Autopano doesn't require much precision, just some overlap.
Well I like experimenting so today I put the Technikardan on one tripod with a 75mm Super Angulon on it and the 5DII on another tripod via a sliding rail. I had no trouble focusing the image on the 5DII using magnified live view. I got a really sharp clear image and could control focus where I wanted even though the two cameras were not connected or even close to being accurately aligned. So I figure if I can do it with a 75, I could probably do it with a much shorter lens on an MF back that is actually attached to the camera. It would really be nice to have live view on the MF, but tethered or LCD review will let me check focus.
Here is the image of my very messy kitchen shot at f11 or 16 (best I recall.) And 100% crops. If a larger 22+ megapixel sensor works as well as the 5DII and give me a 48mmx72mm area (or wider) coverage from my 35mm and 47mm lenses, it will certainly work for me. This will easily put it in the 45 to 60 megapixel range using just three shots in a horizontal row.