I generally use the full-spectrum lights. Lots of people like to mess with the blue and red levels, and debate the benfits of spots vs. flours…But my full spectrums work fine.
The other thing that I do, strangely enough, is have my tank near a window…weird, I know.
Also, I’d avoid incadescent lights. They tend to heat up the water to an unhealthy level, especially in a small tank like the one you have. If you want to grow plants, putting it near a window really isn’t that bad of an idea, as long as you’re ready to spend a lot of time dealing with algae.
I have had good luck with PowerCompact full-spectrum fluorescents. The big qestion is wether you want to grow live plants, or not, and whether those pants are high-light-demand plants or not. My setup - which is currently torn down but ran for some years - had briftwood encrusted with various aquatic ferns and mosses that seemed to do fine under moderate lighting conditions.