You have plenty of poundage and arrow weight. Where I hunt in Namibia, they won't allow any mechanical broad heads. Use a good 2 or 3 blade head. Something you can re-sharpen if needed.
Shot placement is very important. If you are not already aware, the vitals on African animals are further forward than north american animals. It would be worth your time to study this out. There are several books about shot placement on Africa's animals. Most outfitters charge for wounded animals. If you draw blood you have bought an animal. Not saying all of them are this way, but I have heard this from several South Africa hunting operations.
Don't take any shot that you are not sure you can kill the animal. Where I was at, we had many oppertunities at good animals. No shots were taken over 20 yards.