Welcome to the club Matt.
Power Compact Lighting should be enough for a 20gal.Maybe someone in the club has some their not useing they could either sell or give you.If you have just normal florecance you could get some of the soft corals,like mushrooms or leathers untill you get better lighting.
If all goes well,I might have a couple of mushrooms you can have to start your tank (as soon they start to anchore themselves to some rubble)
Cheers
Jim