Im in the middle of getting a 5 1/2 planted nano going. I am using the stock incandescent hood but am replacing the bulbs with the 10 watt screw in CF from Wal-Mart. That will give me approx. 4 watts per gallon. Besides that I am using a small submersable heater, AC20, and proper substrate.
A ten gallon would be perfect for this. Just replace the bulbs with the CF add the substrate and dose with Seachem flourish and maybe Excel if need be. Add some small fish, some nice shrimp and let it go.