I and a hunting buddy handguns into S. Africa last September with no problems. Mine was a single shot Thompson Center scoped handgun and his a Smith & Wesson scoped revolver. We had all of our paperwork done including the "motivation letter" from our outfitter and had no trouble getting through customs. There was a group of 5 hunters at the airport from Denmark who had no motivation letter and were scrambling to get their outfitter to FAX them one. If you have a competent outfitter and travel agent, they should provide you with the forms you need and other information.
You cannot take lever action, pump, automatic or semiautomatic weapons into S. Africa. You cannot take a handgun for "self defense" into S. Africa. If you wish to take a handgun, it should look like a hunting weapon (a scope gives it that appearance). You cannot take in two weapons of the same caliber. A couple of guys were at the airport with two 12 guage shotguns each and were told they would have to leave one at the airport since they couldn't import two of the came caliber.
You also have to be aware of the laws of countries you will be traveling through. Amsterdam, for instance, requires you to have a special permit to go through their airport with firearms in your baggage.
NOTE: Laws change and I think this is especially true of S. Africa fireamrs importation rules. Make sure you have the most up to date information.