Caliber Imput

[Ruddyduck]

I've got two rifles I would want to bring to Africa ,one is a Rem 700 7mm Rem Mag topped with a 3 x 9 and the other is a Win Mdl 70 in 375 H & H with a 1.5 x 6 Zeiss with a # 7 rectile.
I was kicking around the idea of getting a third gun and wanted a little input. I'm kicking around the 416 Rigby or the 458 Win Mag. If I go with the Win I'd probably handload and boost the fps to 2150 neighborhood. Whick do you think would be the better choice?