Stumbled across this link that shows a few more possible power steering donors other than the MR2. Nice thing about some of these is, they eliminate the hydraulic pump part of it. The power assist is done via an electric motor attached directly to the steering shaft, and it looks like it would be a simple swapout rather than a bunch of little parts from all over the car. Almost all the cars listed are 12V only, and I'm pretty sure they come with 120 amp alternators so the power draw's not going to be much. As you can see from the Cobalt unit, the interior steering column bolts to the exterior steering column at the firewall, and the exterior unit has the motor and control unit in a nice, compact little piece, with a short steering shaft going to the rack.