Down in Africa license conversion in Botswana, Tanzania, Namibia, Malawi, and Kenya isn't that big of a deal. Apparently its one of those, take the test, pay the fee, and it doesn't matter what your score is (even if you get a passing score, the bribery factor is still there). Botswana seems to be the least corrupt, with some of the most interesting flying according to what I've read online. Also, the DRC has some flying if you've got some twin turbine experience.
Africa is big up there on my list of places I want to fly.
By the way, South Africa in particular will be a difficult place to find work, as there's no real need for pilots there (there are plenty).
The big operators that I can think of off hand are these:
Coastal Aviation
Nyassa Air Taxi
Sefofane Charters
Air Excel Tanzania
Mack Air
Sefofane seems to be the biggest out there.
checkout maunpilot.blogspot.com or something to that effect, or just google "Maun flying"
It'd be like Alaska flying down there, all VFR, occasional crap weather, with the potential for jacked up loads, and bad equipment. If you do go for it, be careful.
From everything I've read, your best bet is to just show up with a single commerical and an instrument rating and start beating down doors. However, the economy down south is more jacked up than it is here right now, so I'd probably hold out for awhile before making any rash decisions.