Yes, there is a high rate of HIV/AIDS in most African countries. There is also poverty, illiteracy and high crime in certain areas. However, there are also parts of Africa that are more first world than many first world countries I've visited. It's difficult to generalise about any region of the world, but particularly about Africa as it's a land of such enormous contrasts. One would need to take each individual area on it's particular merits rather than looking at the country as a whole (apart from the political situation of course!).
In terms of the country most likely to meet all the criteria, I would say that would have to be Botswana. And, like South Africa, the language of administration is english. However, it's a little too sparsely populated and isolated for my liking!