You don’t say whether you’re looking for metal or plastic. If you don’t mind the latter, have you checked PSR? Most of them are available from places like The Hobby Bunker.
There are a number of sets for the Sudan and Zulu Wars,which would be the places to start. HaT made a box of Ruga Ruga.
And,if you don’t mind a bit of converting, you might look through what’s available in Ancients, Nubians, for instance.
Depends on how accurate you want to be.