Convicts are easiest to breed, but the hardest to sell/get rid of.
Why not do some Angels (6 maybe?) and some rams to hold down the bottem of the tank
If you want to make a SMALL amount of $ off of this i would either go with the Angels, Blue Acaras, or the rams. The Blue Acars and rams will prob. be your best bet for getting rid of and making a small amount of $.
All of these fish are not real hard to breed. But the convicts will pretty much go at it in any water conditions anytime. No help needed pretty much. I was once told by someone on this board - "Convicts can live in a puddle of mud". And really....its almost true.