Good advice from the gents above. Any of the premium bullets noted above should work fine.
You may want to consult some loading manuals and compare terminal ballistics between the 180 and 200-grain bullets. All the premium bullets provide good penetration and weight retention, etc. so it comes down to shot placement and down range energy at point of impact.

Never having hunted Africa, I don't know what typical ranges are that game is taken at, but I'd look at 100 and 200 yards and compare the foot-pounds of energy.
Good luck!