Kevin - good idea. SA is a great place for hour-building, you get to do real long trips with not too many ground references (good to learn sound VFR DR), you learn quick about high density altitudes (particularly if flying from around Johannesburg). I crossed into Botswana and landed at Gaborone Intl Airport, but some guys went on trips to Mozambique, even Namibia! Now that's not in everyone's logbook...
The fuel is cheap, the landing fees likewise, the exchange rate very much in our favour, and it's also interesting for the "touristic" experience.
43 Air School comes highly recommended; check out also Central Flying Academy at Grand Central/Midrand just north of Jo'burg; they're a good lot.
Cheers