Hey bud. I've hunted over there three times. I'm broke now...but man it was worth it! You are in for the treat of your life!
The heaviest bow I ever used was a 55lb. recurve. I had no problem with penetration on any of the animals. On my first two trips...I used arrows in the 650 grain range with a shaving sharp eclipse broadhead. Worked great...even on a huge bull eland that only went 40 yards after the shot. On the last trip...I used a 53lb. Habu recurve and I believe my arrows were only about 560 grains. On this trip, I was going after animals that I had never taken...mostly smaller stuff. I did however kill a gemsbok on the last trip and got excellent penetration. Overall...I would try to use something at least in the 600 grain area. These setups worked for me on 2 kudu bulls, one kudu cow..a red heartebeast, 5 warthogs, an Eland, a gemsbok, an impala, a bushbuck, and a mountain reedbuck. Good luck!