You'll be happy with any of the calibers that folks are recommending. Once you find a rifle you like, take a look at the ballistics. You'll see where all of these calibers shake out.

If you use factory ammo, you'll get a little more power out of a .300 wsm than the .300 win mag, but the best part is you'll utilize a short action. Shorter bolt throw + lighter action means faster follow-up shots (if you need them).

Good luck!