Richie, Good point about adding up watts for switch machines, lights, and accessories. You are right, many wouldn't operate at the same time, but it is easy to add one more item, and pop!--there goes the circuit breaker!
Laker80, the Menards supply sounds like a good choice for lights.
Chris, My shelf looks about like your first photograph. I didn't plan ahead enough to attach track to the shelves before hanging it on the walls. My ceiling is only 7' 4" high, so there isn't much head room to screw down the track. I laid down cork to quiet things a bit, but I think it helps the loose track from shifting from side to side. Make sure your plywood is wide enough in the corners. Mine isn't so each curve has about half the width of GarGraves track suspended in the air. I have seen some folks cut curves in their corner plywood, others cut triangles.
