I've strongly considered just going with an iPhone 5S and always stay one cycle behind and so always get stock easily. But they are still absurdly expensive compared to the iPhone 6, so not really worth it.
(I took a detour from iPhone 4S to Samsung Galaxy S4 and went back to iPhone quite quickly, but by then stopped my contract and somehow got stuck on an ageing iphone)
Don't bother. There are no 32GB or 64GB 5Ss available in SA right now. Telkom is only handing out 16GB models. iStore says they're waiting on the next shipment of 6s which they *hope* will include a batch of 5Ss.
WTA.