How far are you shooting on average? What kind of country? Flat, steep, wooded, etc? That would affect my decision. Of the three, the 7mm Rem Mag would be the most versatile. You could load light for a flat shooting round in open country or you can load heavy for timber. You can even load in the middle if you hunt windy country.
With that said, get a 300 Win Mag! 150gr Swift Scirrocco is a great open country, medium game load. Shoots super flat, hits hard, takes animals down hard.
