Sorry, but I've been in photography for a very long time, and I don't think "stable shutter at slow speeds" should be (or is) included in the list of "pro" options. I have a $500 point and shoot that is stable at slow shutter speeds (and yes, I know it doesn't have a mirror). It seems to me if this is a legitmate issue, it is something that comes under the heading of "If we can't do this part right, why put out the camera at all?". (It does beg the question, why have a mirror in a digital camera anyway? Why not just get a video feed to the viewfinder, same as on the point & shoots?).
As for the 1DM2, why spend more than you need for something? I spent the last 5 years of my film life shooting with a Nikon F100 body, never owned or needed an F5. There are a lot of features in the top of the line bodies from all manufacturers that most people will never need, so why pay extra to not use them? For his purposes, the 20D has all the technical specs and features he needs, as the 5D does for me. But as I said, I don't think eliminating "camera shake" should require a massive upgrade.
Regards,
Andy Pearlman
Andy Pearlman Studio