Much simpler just to open a dollar denominated account with your bank if all you're looking for is a Rand/$ hedge. Unless you're talking millions in which case I wouldn't risk BTC anyway. Otherwise if you're prepared to risk holding/speculating in BTC why not just buy BTC and hold it in BTC on BitX without the Bitfinex conversion?
I'm now trying to find out what fees will be involved, but previously I assumed fees/expenses would be quite high.