Are there any UK citizens who have experience of doing a PhD in South African universities? How good are the good ones? eg UCT or Witswatersrand.

Sorry, can't answer your question... but tell me are there any scholarships available for us Brits to do this?

Visit http://education.pwv.gov.za/DoE_Sites/Higher_Education/Opp_HE/opportunities_in_higher_educatio.htm for a list of higher education scholarships in South Africa.