Get a pictus. i've had mine for a year now, and he's only grown from 4" to MAYBE 5". And I do weekly 75% water changes, so the water is super clean, and all of my cichlids are growing like mad. Most of them, I don't believe get as big as people think. That, or they are just SUPER slow growers.
And I've had 4 pictus cats now. I've had ones that just lay in a cave all day and are super lazy, and I've had a few that swim absolutely non stop, and are like the freaking energizer bunny. Check them out in the tank you're buying them from, and get the disposition you want.
Pictus are my favorite. They are just plain awesome. Get one.....You'll love it!
Oh.....And remember to NOT use a net. They'll get stuck in it for sure with their barbs. I learned the hard way. Had to cut them out of the net (cut the net not the fish.....obviously, but just for clarification since that reads weird). And don't pick them up with your hand. They'll cut you. I've found that tupperware works best.