For an adult Featherfin? I would look to what else inhabits the same region.
Tilapia sp are found in West African rivers and should be more than hardy enough to manage even an aggressive Featherfin. The most common one if, of course, T. buttikoferi, and anyone who's kept a Butti will assure you they're quite able to look after themselves

Some species of one of my favourite fish, Bichirs, also come from that region. The Senegal Bichir would probably be one of the most common and readily available of the West African Bichirs, as well as being one of the smaller ones. I have an albino Senegal and he is ridiculously friendly, certainly on a par with my Dat and my Oscar
For smaller cichlids, you could look at fish like Jewel Cichlids, Hemichromis bimaculatus. Again, anyone who's ever kept Jewell will tell you they're tough little fish.
How about a Spiney Eel? Some of the members of the Mastacembelus family are found in that region. The Tire Track might be a little large for your tank, but some of the other species would probably work.
There are plenty of other species that I just don't know enough about to recommend that would work as well.