Most common Tanganyikan fish...
Shelldwellers- most all will do fine, stay small, easy to spawn (look for 'lamprologus' brevis, 'lamprologus' ocellatus, or neolamprologus multifaciatus)
altolamprologus calvus- sometimes, will compete over rock space, but only mildly aggressive
cyprichromis leptosoma- "non jumbo" variants, 55+ gallon (need large groups, 8 minimum), pretty delicate...and relatively expensive, open-water schoolers
paracyprichromis species- similar in size and shape to c. leptosoma only not schooling, still prefer groups, generally hang in rocky areas
sandsifters (Xenotilapia)- may work but highly unlikely as they need large open areas of sand at bottom, not very hardy and startle more easily
neolamprologus brichardi- can be highly aggressive around breeding time, a single male might do well but a lot of rockwork must be provided for territory