Richard,
What's on the menu for Africa? If you're going for buff, 375 is the legal minimum in most places, although, sometimes, you can get away with a 9.3x74r, which is generally quite adequate from a performance standpoint.
You might want to consider the Chapuis, which (esp in 9.3) can be had for a reasonable price. The one I'm familiar with is quite accurate (2" at 100 yds with scope) and handles well. Otherwise, you'll pay a premium for 375 or larger. Used to be 450/400s were easily available on the aftermarket, but with ammo becoming easy to get, people have discovered how good that family is.
As for needing an ele stopper in Californis....you can never tell.
