Thank you all for your recommendations!
We have decided to go with -
JNB > CPT immediately; stay in CPT for 4 days; CPT > MQP; 2 days @ Kruger (Skukuza Rest Camp); MQP > JNB; JNB > Home
This game plan will allow us to see most of what we would like and get the most out of the short time we have there. Greatly looking forward to it!