I posted to this blog last year, asking who to use to register a .co.za domain because I had some bad experiences with some of the bigger South-African (not mentioning any names, of course) domain registrars.
I have subsequently found that the easiest, quickest, cheapest is to do it yourself. It only costs R50-00 a year (much better than the exhorbatant R200/year some registrars charge) and only takes 10 minutes to do (be that in a slightly archaic way). But the best thing about this is the absolute control you have. There are no 3rd parties involved (i.e no registrars pleading ignorance about changing DNS settings so that you HAVE to host with them etc). You set up your all YOUR contact info, DNS settings and all the rest.
The way to do it yourself is very straight forward. All you have to do is to go to the co.za Domain Administration homepage and click on the HowTo guide link. This explains it all.
I have recently registered The Red Apple in this fashion and it runs of my Brinkster (in the US) account. Exactly how I want it.