Little to add to this that hasn't been said. I am a huge fan of the .338 WM and had great success with it on my first trip to Namibia which included some very long shots in the Erongo Mountain region. On the same trip, my son used and '06, and though we recovered everything, the 180 gr fusions were not a good choice (great accuracy but so-so penetration). Any of the .33 cal calibers would be similar to the WM at the animal's end of the trajectory. Next year, for a pure plains game hunt, I'll use a .318 Westley Richards (.318 British measurement - .33 U.S.) Last year, with buffalo on the card, I used a .375 for everything - it worked great as well. As someone else noted, I expect more PH's have .300 WM's as camp guns than any other caliber.

For a first trip, I don't think I would recomend the 7-08 as an optimum choice. It absolutely will work, but it leaves you less margin for error and you will have fewer exit wounds on the larger Plains Game. If you haven't done this before in Africa, shooting over sticks with a critical audience is different. You need to shoot quickly, accurately, and something decisive needs to happen at the other end. If you are placing those bullets correctly, you also are well forward of where you would be on a deer and you often will be driving through bones. A 200+ gr premium bullet from a .33 does that awfully well.

"We sleep peaceably in our beds because rough men stand ready in the
night to visit violence on those who would do us harm" Winston Churchill