I shoot both and have shot a lot of game including Buffalo with both the 375 and 9.3x62..both are excellent.

The 375 is the more practical and the most powerful of the two anyway you cut it and can be loaded down to duplicate the 9.3x62 and still have a better cross section of bullet, and that spells killing power....

But in your situation based on your post I would go with the wonderful 9.3x62 in a nice light trim slim rifle with at least a 24 inch barrel..The 9.3x62 needs a little boost in velocity IMO and I shoot a 26 inch skinny gun and I love it....