The only African cichlids that may be suitable are Kribensis (kribs), all the rest are not community fish and should not be kept in community tanks.
Whether kribs are possible would depend on the size and dimensions of your tank. You also need to consider that a pair of kribs (male and female) are very aggressive when spawning, which could stress your existing fish. Doesn't mean its not a possibility but worth considering, do some research.
Another option and a safer one IMO, would be a pair of Rams. They are not African but generally do better in community tanks, again dependant on your tank size, look them up in the new world forum, and you'll get lots of info.