Sorry to say but there is no such entity in South Africa...
There are however very reputable, regulated and trustworthy international ECN brokers who offer interbank liquidity and very low commissions and spreads, with instant execution across an array of order types (limit, stop, market, oco, hedging, etc)
You are literally out of your mind if you want to trade anything on margin with these Fx bucket shops we have here... Rather take your money offshore into a currency that is relatively cheap currently in dollar terms if you are afraid of local currency appreciation relative to the Dollar...
Think GBP, NZD, AUD, CAD...
Have a look at brokers like pepperstone, tickmill, dukascopy (jforex not mt4)... I use all three of the above in live trades and have never had any issues with payment, execution, spreads, lag, slippage, etc... Even during news releases...
This is going off-topic, maybe we should start a separate thread to continue this discussion in earnest...