1-2 shop light clip on domes or reptile dome and 1-2 6700K 13W CFL's. If you want it to look fancy and can do a bit of woodwork and electrical, buy 1-2 light sockets, make a hood, wire them up. If you have tools and scrap wood, you could probably do a 2 fixture unit and wire it yourself for 10-20$. Using reptile or shop domes, they are a bit more expensive.
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.