I've read about conduit pipe as well, and might try to go that route.
One idea I've had for the fixtures is simply taking a clamp light from Home Depot and remove the clamp. I would then likely cover the actual housing with something a little more attractive, like a cheap mixing bowl drilled and painted as you mentioned. The clamp lights are about $8 dollars and are already wired.
Hoping to start on this around Christmas and be done sometime mid-late January. I'll post pics when available.
Interested to see the outcome of yours, love your idea and I plan on pirating much of your design for my own stand!