A hunt to Masailand TZ is being planned for the future for Buff/Plains game hoping for 2 Buff.

Calibers available-7Mag,300mag,338Mag,375H&H,416Mag,458WM,470NE and others--
CONSIDERING the Terrain and game---
What would be the best 2 Calibers(among those mentioned) to carry? WHY?

A 470NE Double and a scoped 375H&H?
A 470NE Double and a scoped 416?
Two scoped 416's or 375H&H's(i.e. a 2nd one for b/u)?
A scoped 416 and a open sighted bolt 458WM?
A dedicated Buff gun and a 300 mag for Plains game?
Other suggestions?

Thanks to members of this forum for any suggestions beforehand!!!