FishNeedIt sells 70W metal halide fixtures for about $100. I have one hanging over my 10gal nano and it works great. I've got zoas, some LPS, a kenya tree and a tube anemone in it, and everything is growing nicely. My recommendation, if you decide to go this route, is to order it with a 20k bulb, because the small bulbs don't seem to hold that nice white/blue color like the bigger bulbs do.