What would you do?

Caliber aside, you want to be able to shoot at least a 180 grain bullet to have enough energy out past 600-700 yards so that limits your choices.
Start at 7PRC and go up.
The 300 WIN MAG is probably the best overall choice for ample assortment of factory rounds and the ability to hand load to sub 1/2 MOA on custom rigs.
 
Top