I would say have a breeding pair or a single oscar with other fish in the tank. An oscar as a centerpeice with a sev, a jd or gt, and a few cons or firemouths makes a nice cichlid tank. You can get a couple breeds of cats to go with them and most species of pleco (just have to make sure the pleco gets big enough so it isnt food for the bigger fish).
PM a mod or respost this topic in the new world section and you will get more cichlid focused people to answer your ?'s