If you really want some good info and input on what to put in your tank contact Jeff Rapps and Tangled up in cichlds. He has the largest selection of central and south american cichlids both large and small species. I would say 95% of my cichlids come from him and his fish are true to breed, no hybrids. I would stay with the less aggressive smaller species which usually works better in a smaller tank. You could even get some pairs and possibly even breed them. Good luck with you cichlid tank.
Tangled up in Cichlids
Phone: (908) 387-9858