...and here's the light that I'm using, temporarily.
This is just a single 39-watt T5 HO lamp with ballast and reflector, but it produces surprisingly bright light. I could probably get along with a light like this (without the rustic hanging job) with the right plant selection. However, I think that I do want somewhat brighter light. I am considering investing in this fixture when I get closer to a permanent setup:
Aqua Medic Sunbeam 36"