I'd go with the 180.

IMO even though the 180 is a good .30 caliber bullet, the 165gr bullet is best for .30 calibers. Speed of a 150 and knockdown power of a 180.

Many 30 caliber nuts (of which I certainly am) simply think that if 180grains is good, 200 must be better. In actuality most 30cals will yield better penetration with quality 180s than they do with 200s. Most of them simply don't develope enough velocity to drive a 200 fast enough to perform too its potential. Some of the super 30s will drive 200s plenty fast, but realistically there aren't as many quality 200s out there as there are 180s and the 180s will completely penetrate elk sized game when fired at such velocity so what more is needed?

Stick with TSX, FailSafes etc or at least the newer "bonded" type pills like AccuBonds, Trophy Bondeds etc and you wont have a minutes problem from that 300WSM (or anyother 30cal for that matter),
RA

well I have 2 boxes of Nosler Partion 180 gr .308 leftover from my 30-06 that I bought to load up for a moose hunt in BC 15 years ago where I literally dropped a 1200# bull in his tracks with them. Think I'll load some up in my 300WSM over a stout powder charge to test for accuracy at 3000fps.
As shots will be under 200 yds I may take my 45-70 with 405 gr bullets along zipping along at 1900fps just for the fun of it.
The biggest animal in weight I plan to hunt is a zebra and I can't imagine one going too far with either of these calibers bullets busting thru his shoulders.

I will assume you're a handloader. There aren't any factory loaded cases with a 200 gr bullet. I'm sure you're using a factory rifle that has a short action. If you load the 200 gr. you will be deep into the case and use up a lot of powder space. I think you will do much better with a controlled expansion 180 gr. or even go with a Barnes or Fail Safe in 165 gr. and you will have all the penetration and knock down that you need. With the Barnes or Fail Safe on broadside shots you will probably get complete pass thru's. So if you want pass thru's go with the above mentioned. If you want to dump all the energy look to one of the bonded core types in a 180 gr. If you have the money to go to Africa I'm sure you're an accomplished rifleman and will make good shot so the game won't know if they were shot with an X bullet or a partition. Down is down in the hunting world. Good luck and good hunting.

"have enough money to go to Africa" it costs more to go to Montana buy an elk lisc. and hunt elk for a week than it costs to fly to Namibia,hunt 8 days,pay trophy fees,and fly home again.
I know I did it an killed a nice 6x6 a couple years ago. I only wish I could afford to do it again without doing the drop camp thing.