no 5 inch african cichlids would work in a 15 gal if you want my opinion. go for a bigger tank if you want the larger africans. otherwise, there are some nice smaller africans, shell dwellers from lake tang., taht would be okay in a 15 gallon. do a little research on them.
also, if there were posted in African Cichlids section, you'd get more response from african cichlid keepers