Can anyone help with information regarding NZers in SA Forces.

I am also looking for information for a Tpr Anthony John Sarich (aka as Jack) late 2nd Light Horse, General Both's Campaign, German West Africa. Died at Johannesburg Hospital, November 26, 1915, Aged 36 years. I understand Sarich has a mining background and was a miner in Africa, presumably at the outset of WW1. Any information about other NZs who may have been mining and enlisted in SA would also be welcome. Also can anyone advise where can I get SA WW1 enlistment info please. Tpr A J Sarich is not currently listed on CWGC.