Welcome to the site. I don't have any experience with photo vests, but I did recently go to Africa. (South Africa) What time of year are you going to be going? I was there at the end of May and the temps were perfect. I would have had no problem wearing a vest and staying cool. We had temps in the mis 70's all week and we spent most of our time on safari in the back of a truck. It's not like we were doing a lot of hiking to get warmed up.

That vest looks pretty decent to me and the price seams pretty good too. I have seen photo vests sell for 2 or 3 times that price.