12V? Not possible with repro antique bulbs, and the high amperage would make it worse, IMO. We're talking maybe 20 or 30 bulbs around the walls of a room, near the ceiling. I'd guess around 1000 watts total.
*Personally*, I don't see why there would be a problem with this in common sense terms. I'd simply mount the sockets at 7ft (same minimum for equally-dangerous ceiling fans), use a box in the wall as normal, and have some sort of decorative fixture to transition from the box wiring to the cleat wiring.
