it depends on you, there are about 15 major universities in SA, with University of cape town, university of Pretoria and university of kwazulu-natal topping the lot, but they are more expensive than the others. with SSCE, they would most likely not take you directly into 1st year, they'll probably take you into a pre-degree year first cos they always want A-levels. UCT will cost you about R100,000 per annum while the others you'll pay about R80,000 tuition fees only, accommodation, books and feeding exclusive. In the other schools like university of Witwatersrand, nelson mandela met. university, university of Johannesburg, you'll be paying like R60,000. exchange rate should be like R1 to N15 now.
all you need to do is to go on the university's website, look for international office or international students, you'll find e-mail contacts there, then tell them what you want to do, they'll handle it for you, I know individual departments don't handle admissions for international students. tell them to also give you estimates of costs for next year.
you may find this site useful -
http://www.southafrica.info/about/education/universities.htmtake care.