Hi Lesley,
Rand is the main currency in South Africa so if you wanted to take cash, I would advise to change whilst still in the UK. Rand comes in coins of 1,2 and 5 and notes of 10,20,50,100 and 200.
Travellers cheques are excepted in banks, hotels, restaurants and shops. To avoid additional exchange rates I would advise to take cheques in pounds sterling or US dollars. Most credit cards are excepted including Master Card, Visa and American Express.
I hope this helps Lesley. If you need anymore information, please do not hesitate to ask.
Warm wishes,
Cheryl, your editor