I can see the Proteas dominating cricket like past West Indian and Australian sides. Starting with Alviro Pieterson, the guy has had plenty of chances to cement his position and although technically superb there is something stopping him from getting to where he needs to be and that is to pile on runs consistently, the odd ton here and there is just not good enough specially now that father time has caught up with him. If there is no younger substitute, and here my thinking is Quentin De Kock, then I would fast track Faf as his replacement. I may be wrong but Faf would bring some much needed fire into the top order, besides scoring quickly he also brings stabilty.
Next to go would be Tahir and Robin Pietersen, although the idea of a 4 pronged pace attack seems tempting I would be looking for an allrounder role in JP Duminy. We all know what he can do with the bat, not to mention that he is a useful spinner of the ball which makes him the ideal candidate. All that's needed is for JP to bowl between 10-15 overs per innings and let's face it Robin is better suited to the ODI than Test cricket and JP spins the ball a lot more than what he does. Tahir is a proven failure.
Spoilt for choice with pace these days, when conditions suit, I would front with an all pace attack, take your pick between De lange and Kleinveldt, both are equally good enough to fullfill the role. Over rates of course are a daunting challenge for sides with an allpace attack, ask the West Indies of old, fines are at a premium.