Hi Sandy
There are quiet a few options. My preference would be to take most of it in cash (South African rand) but also take my bank cards with me so I can withdraw more cash if I need it. It's worth letting your bank know if you plan to do this.
Other options are Travellers' Cheques, which can be tricky to change, and pre-paid travel cash cards, which the Post Office offers. I haven't used one myself but some travellers like them.
Other Community users might have some opinions for you too.
Kind regards,
Olly, your editor