I currently use a Capitec account for emergency funding as it available immediately.
I have a Virgin Money credit card. Reason is there is no monthly charge to have that card and 55 days interest free.
I added the credit card as a beneficiary on Capitec, so if I need cash fast I can use Credit card and transfer from Capitec.
I know its not the highest interest rate @ 5.3% but, it's simple and doesn't cost anything cause interest earned is far greater than admin fee.