Travel in South Africa is so easy and so rewarding. We've only traveled there independently, staying 7 weeks the first time and 6 weeks last year. You can drink the water everywhere, the roads are better than those in the northern half of the US, everyone is friendly and helpful.
If you like wines, they are excellent and incredibly cheap. Many are VERY close to Capetown and most have a museum, a cheetah sanctuary, a restaurant, etc. We brought back boxed wines because they are more resilient than bottles for shipping.
The only warning we'd give is that Capetown is located where two oceans meet and the weather can change rapidly. If you see sun, go out and enjoy because it could be cloudy the next day.
Eat EVERYTHING. Despite their heritage of British and Dutch foods (neither too interesting to me), the South Africans have put together the best foods ever. Bobotie, Koeksisters, lamb 100 ways, and game meats. Their avocados don't turn brown in the air, they grow their own small sweet pineapples. The list could go on for pages.
The animals in the parks, especially Kruger, make SA the best place we have ever visited.