Well that narrows it down to African cichlids..which there are thousands of species lol.
However I would say there are no cichlids I'm aware of that can live with your cray. I agree with Trevor..you would like the shell dwellers..well at least they are appropriate for your tank.
lol... and trevor true..kinda. There are dwarf Mbunas but they make up for the dwarf part with aggressive "large" personalities usually. Not anything suitable for a small tank. Curious though... are you looking to keep 1 fish in your 29 or a few?
I actually like the idea of one or two large-ish fish compared to a ton of small ones.