Sorry i missed the other question.
Glad to hear you have babies, i should start doing that when my striped pair spawn next time.
I have a chance to pick up a boat load of cheap females at a LFS i might go grab them and start feeder farming since i can rotate males and give the females more than enough down time.
Anyhow to focus aggression in my convicts anything will work. I try not to use something that might be able to sneak past them at night and get the eggs. So i avoid catfish and plecos. In my display tank its the catfish that eventually get the free swimmers at night....or the midas and jag rush the parents together during the day.
I'd recomend something mid to top water, cheap and fast. giant danio come to mind but rainbowfish or silver dollars might work. Silver dollars might get beat up though depending on the size of the cons and the tank.
Sometimes if you have one of the transparent tank dividers you can put another pair on the other side and they'll spend a good deal of time trying to kill each other through the divider and that has helped a couple pairs do well for me (in a ten gallon actually, they werent supposed to breed during the quarentine period...but hell i'm not going to argue with them).
Hope this helps somewhat
Jason
PS some people use a mirror on the end of the tank. i've done it but i've had mixed results with my smaller cichlids. My curviceps pair was never the same after a mirror, they'd always turn on each other and eat the eggs, might just have been them though. Convicts breed like mice so i think it might pass with them.