There are about 1000 different species of African cichlids, some would work, some would not. You need to be a bit more specific. Some Africans come from soft water, some from hard water.
Many of the soft to neutral water varieties would work, although some may be too aggressive.
If your Geos are an aquarium strain that has been brought up in normal water conditions of your area, some of the hard water Africans may work, but then again, some are too aggressive, some not.
Your signature suggests (?) you may be from Long Beach CA, I just googled the LB water quality report, and it looks like your tap water parameters are perfect for rift lake African cichlids, I'd venture to say you could have the non-aggressive kind with your Geos.
Cyprichromis might work, but any of the mbuna would seem to me, too aggressive.
I have kept Madagascans with Geos successfully, but they are not really Africans.
