I found the bulbs at Wal-Mart for $7 a two-pack.

They are the GE 6500K Daylight, not sure what wattage but they have a lifetime warranty, and the light is perfect.
The bags are just regular old white trash bags (13 gallon, I think? The normal size.) cut down two sides. There is a seam dead in the center running vertically, taped with wide clear cellophane tape, but it isn't noticeable. Honestly, though, I'm going to redo the material soon, it's too thin. I bought a few rolls of thin off-white vellum paper at Michael's I want to try. It's that or double the trash bags, which will work as well. From what I've heard, drafting paper works best. The really, really thin kind that comes in huge rolls. I just couldn't find any locally.
I'll post some pics once I get it all put back together.