As a South African we were only recommended to get a hepatitis shot before coming to Korea but it was our choice. As far as getting vaccinations to go to South Africa goes I have heard of people getting a ridiculous amount as a precaution and other people not getting any at all, I suppose it depends how paranoid/safe you want to be. The main things that I would look into is cholera(I don't know if there is a vaccine for that?), and the medicine resistant TB. Otherwise everything else is treatable, well not AIDS :o
Enjoy SA, very jealous.