If you open a trading account in ZAR as the base currency, you will save on the conversion fee when depositing or withdrawing money. However, this option is not very popular, so most global brokers provide accounts in USD, GBP, and a few other currencies. Yet, simply choosing your broker based on this sole criterion is not very profitable, because the other costs your local broker charges may be much higher than the conversion fee charged by a global broker like AvaTrade.