Youre pretty well rounded really... you have aggressive and passive... you could pretty much get any mbuna. Only thing with your tank is you have groups instead of single fish, so if you do get any other fish, i think itd be best to introduce groups at a time. I just ordered from tampa bay cichlids and ill let you know how it goes. They have a pretty good selections and if you spend over $49 the shipping is free for 2-3 day shipping. If you choose over night and you spend over $49, the over night costs are discounted down to like $24 i think