That will be a good idea, I don't know how people use there PayPal account in Nigeria despite the restrictions, it seems like they are people that have a working PayPal account or something.There is absolutely nothing special about PayPal that other payment gateway do not offer.
You will not force them to accept locations they do not have in their plans to operate on and from all I am seeing there is no indication that they will start accepting those locations they have not operated on anytime soon.