My family and I are currently working in South Korea. We are South African, how can we get a China visa in South Korea?

Yes, you should apply for visas to China through a travel agency appointed by Chinese embassy or consulate where your application should be submitted to. The travel agency will work on your behalf for China visa application. Your personal appearance is not needed unless visa officers require for. Be also note that you are required to provide ARC valid for more than 6 months if you want to apply for a China visa in South Korea. (I get information from other applicants that Busan consulate is not very strict about ARC.) Other documents you need to prepare are your passport valid for more than 6 months, application forms for China, photo. It is also helpful if you provide return ticket and hotel bookings in China, as well as a bank certificate to cover your travel expense.