I have been itching to pick up "one more fish." I know we've probably all said it and then bought like 5 more at some point, but hey. . . 
Would my GT be okay with one or two convicts and one featherfin synodontis catfish in a 55 gallon? I know my signature says rainbow fish right now, but really, they are only there until the other guy(s) get big. If one or two cons IS okay then what would be the wisest combo of male and or female? Two males, or two females? A breeding pair would be out of the question right?
If not cons, then are there other smallish cichlids that might work, besides firemouths?

Would my GT be okay with one or two convicts and one featherfin synodontis catfish in a 55 gallon? I know my signature says rainbow fish right now, but really, they are only there until the other guy(s) get big. If one or two cons IS okay then what would be the wisest combo of male and or female? Two males, or two females? A breeding pair would be out of the question right?
If not cons, then are there other smallish cichlids that might work, besides firemouths?