You could get a backpac PS with that set up. Looks promising and I'd be interested in seeing it. What kinds of fish are you interested in? aggressive, community, species only? Your choices are limited but not as much as your 10 gallon. Peaceful community works well cause later on you can add corals, aggressive..you have very few choices. A schooling tank would be impressive, something flashy, orange stripe cardinals, Pj cardinals, even yellow belly blue damsels one of the "nicer" damsels, indigo blue chromis, green chromis are very peaceful and they acually school..they even school with other fish. Almost all damsels will school, but they are agressive and will be mean to anything else you put in there..they will even attack you given half the chance. I have a blue damsel that bites me every chance he gets..he is in with a yellow tail damsel and a Pseudochromis. It's really up to you, just make wise choices and always look to future goals..what is it you really want, work from there and make it happen..hey you can always get more tanks!