How about big snails, Rex? Think your cichlids would mess with those?
The only other thing I could think of is shrimp. I know my rams don't mess with my amano shrimp at all but maybe a different cichlid would make a meal of 'em. Maybe you could find some of the larger ghost shrimp that seem to be floating around right now. I know my ghosts eat some algae (but the amanos are better).
Wish I could offer more but my plecos have been the answer to most of my algae problems!