stingrays, gars and payara (saber tusk barracuda) get to large and the payara are not a good choice unless you have lots of experience.
Trout will require a chiller.
Silver dollars destroy plants but make a great stert to a SA community tank.
I like eels but you will need to narrow it down some, there are lots of things called eels.
I think africans would do nicely. You just have to decide what type you want to do first. Also there are quite a few catfish species that work well with africans.