Do it, you won't regret it. The garden route is a fabulous part of the world and it is all the better from the air. Cape Town - Plettenberg Bay or George is an easy flight and at Plett you can get a ride into town in ten minutes (or hire a car) to drive to Storms River/Tsitsikamma National Park. From George it is a quick short drive to Wilderness and Knysna - all worth a visit.
Make sure you do a low pass through the Knysna lagoon and take full advantage of SA's lax 500' rule!
Negotiating George's class C is a little bizarre if you're used to the UK where controlled airspace is a radar environment - they're full procedural as there's no radar (plus the controller is also the tower at George so he's often busy with circuit traffic), so make sure you know the VRPs (Albertinia and Sedgefield, from memory)
My CPL qualifying cross country was Plettenberg Bay - Beaufort West - Swellendam - (Garden Route) - Plettenberg Bay. Ahhh memories...
cheers!
foggy.