KEB only charges an 8000KRW fee for overseas transfers, and their internet banking service is really user friendly. Because you convert the won directly to Rands, you lose less money. Also, the BEST thing about KEB is that it is guaranteed that there will be at least one English-speaking clerk at every branch.
Their phone banking system is also great. If you get a little stuck with internet banking the first time, they can help you out.