I don't entirely agree with the above post. Convicts can be too aggressive for blue acara, I am not one for mixing New and old world Cichlids, because their needs and behavior are so different, so for me the yellow labs are out. Firemouth's would be OK. A shoal of Tiger barbs or any large barbs would be fine. I have clown barbs in with my con's. How about something like Archocentras Centrachus, they are a nice fish and don't get too big and are from Central America, the same as a convict.
Senegal might struggle for food depending on the amount of convicts as theyre slow eaters and take a wile to find food