@ OP - Went over recently (Aug) , just when i applied the application process was extended to 6 weeks , so would really think of submitting ASAP.
Required papers :
Proof of employment with a letter of leave from the company of the dates out of S.A.
Proof of Address , plus a recent rates bill and a bank Statement.
Valid Passport with no less than 6 months to expiry date.
If you are visiting friends or family, a letter of invitation from them with the dates and their address.
You will be required to go for a biometric test as well.
I went through an agency for the sake of convenience, rather than struggle with all the correspondence personally.
On their home page check country and number of visa's, a second page pops up with all the info and documents required, really helpfull.
https://visaexpress.co.za/
P.S try not to fly Quantas to and from Australia, their planes are old, the seating is cramped and the service is rather mediocre.
Also any smokers travelling with you , no more than 50 ciggies allowed into Aus per person. Customs will rip you 136 AUS$ for a carton even if you bought it duty free prior to departure.