I recently purchased an african cichlid, yellow lab, and I have to say hes awesome!!! Hes aggressive at feedign times but doesnt hurt my other fish, hes good looking, and hes not afraid of anyone, some fish spook off if an unfamiliar face gets in front of the tank but not him, Id say go with some african cichlids. Also you could get a used 75g off craigslist for about the same price as a 55g, you just have to find one but keep looking, 55s are good too and theyre all over the place, dont pay more than 50 bucks for a 55g unless it comes with stuff, I say add ten for filter and ten for stand, roughly. But being from florida fish tanks are common, dont know how it is where youre at