oops, double post ealier.
I was also thinking for a light on a 10 or 15 gallon, you could also get away with either a single 65 watt pc bulb or a 2x40 watt pc fixture. But, I think the single 65 watt only comes in 24" size and a 10 gallon is only 20". At any rate, you should shoot for at least 4 to 5 watts per gallon, and usually the more the merrier. You might be able to find a light for as cheap as $60 to $75, but plan on $100 to $120 to be safe. Also, check out Reef Central and Nano-Reef.com for used lights. I hope you have been to Nano-Reef.com - it is great!!
My 25 gallon has been up for 9 months and is doing great. I prefer soft corals, I don't like the look of hard corals. I have several colors of mushrooms, a couple different zooanthids, a cabbage coral, tree coral, lots of pulsing xenia, button polyps, star polyps and a candy cane. I have 4 fish - which is the max for my tank size. Handful of hermits and snails, too. I have 35 to 40 pounds of liverock - I think you should get as much liverock as you can - that is your filtration system. Try for at least 1 1/2 pound per gallon.
I have a CSL light fixture which is great because it has a moonlight included - very cool. I just recently added a Remora skimmer, but it seemed to do just fine without a skimmer.
Beth.