For tough skinned animals like wildebeest, zebra etc at longer distances the best would probably be 300 win mag or 7mm rem mag. It is only when you hunt something that can bite scratch or claw that you that you need a 375. I (being South African) hunt here regularly and my most used rifle is a 7mm rem mag. If you hunt at shorter distances in the bushveldt, the 375 is good (not so much deflection through the bushes).
Which area do you plan on hunting in?
Charls