If you have a mbuna type then I would suggest putting a common plec or a rhyno plec as they are good and tough fish that will take a beating...However if you have a hap and peacock tank then you could put some syndonotis species in there, same as clown loaches or any type of plec you like....I keep 3 fancy plecs in my tank and they are un harmed.....
rusty plecos are great for an african setup, mines doing really well in a frontosa tank and they eat fish , if you went with an mbuna setup this would be ideal too.