What towns are you going? Joburg/ Cape Town/ Durban? A few of us on here have lived in SA and are more than happy to provide some recommendations but we need more specifics - how long are you going for, what time of year, what are your interests?
Perhaps you may enjoy Stellenbosch and Plettenberg Bay more than Kruger. Who all is going, how many kids, etc? A safari vacation is very different from a vacation with a few days of going on a safari. Look into Sun City/Lost City and the neighboring Pilanesburg game reserve.
Give us some structure around the trip and we can help.
-Sam