Hi Pat
Northern Kruger is buzzing at the moment because there have been good rains. iI dont know what it will be like next October - it tends to be a bit dry up there. However, the bird life is always good. If you enter thrugh the Punda gate (594km from JHB) you could stay at Punda Maria to start with and work down. Whilst at Punda, explore north and visit Parfuri (look for Frank who will be able to show you some birds there)and travel the Luvuvhu loop. I don't know whether you prefer the quieter camps or the larger ones, but you have a nice choice of both as you move south. You could finish up at Letaba or Olifants and leave via the Phalaborwa gate (520km to JHB).
The Berg: Tendele camp at Royal Natal is lovely. If you book in there, ask to be in the upper camp. it has the most stunning view of the amphitheatre and has indigenous forest at the back. There is a short walk through the forest - if you do this in the morning/afternoon you should see plenty of birds. There is also a lovely walk to Tiger falls from here - lots of sunbirds and grassland birds. Plenty of other good walks too. Just watch for baboons stealing from your chalet! Dont go away and leave anythihg open! From there, it is approx 1h30m day drive to a place called Spionkop Nature reserve on the edge of Spionkop dam - good bushveld birds there as well,plus rhino, giraffe, zebra wildebeeste, kudu, jackal, impala, hartebeeste, eland,etc. You need to aim to arrive reasonably early to get the best bird life. it has picnic spots and loos.
This part of the berg would be the closest to JHB (I think its about 4 - 5 hrs). Lots of other lovely Berg areas though. If you go further south,you could arrange for a bird guide to take you up Sani pass for a day (or even overnight) . If you want the name of a guide, let me know.
Good luck in the planning. Feel free to ask more questions.