If you arrive to South Africa Via

 Johannesburg

Start by going to the Kruger park via the Panorama route first, then return to Johannesburg (4 hours drive) and fly to Port Elizabeth to do the Garden Route and finish in Cape Town.

Alternative option is to continue from the Kruger Park, south to St Lucia Estuary via Swaziland, Finishing in Durban and Flying to Port Elizabeth to continue through the Garden Route all the way to Cape Town.

You need at least 2 Full days in the Kruger Park, One day in St Lucia, One day in Durban, 3 Days for the Garden Route.

 

If you arrive to South Africa Via

 Cape Town

Start by visitng Cape Town and the surrounds (3 days at least), then take a Garden Route tour finishing in Port Elizabeth  (3 days) and then fly to Johannesburg. From here take a tour to Kruger park and Panorama Route 3 days at least.

Alternate is to Fly from Port Eelizabeth to Durban and travel to St Lucia Estuary (2 Days) and then the Kruger park via Swaziland (3 days). From the Kruger park, return to Johannesburg via Panorama Route (1 day).

Alternative Visits

Fly to Upington and visit Augrabies falls (2 days) and the Kgalagadi National park (2 days)

From Johannesburg you can take a tour to the Drakensberg Mountains  and Golden gate National Park (at least 3 days)

From Cape town you can Tour the West Coast including the Flowers of the Namaqualand (mid September to end september only) and you can take a trip to Augrabies falls and the Richtersveld nationl Park (4 Days at least)