If you’re bent on the 30’s I’d stick with the 300 Win myself. Great brass is everywhere I hate being shoehorned into one or two kinds of brass. With Lapua, RWS, ADG and other great options abound. Good stuff is there for the PRC but not easy to get.
Throated for a great bullet like the 208 or 212 ELD puts you in a decent place for bullets.
I think if you run the numbers a well set up 7 Rem or similar is really tough to whoop and the 7 will do it with a little less beating on the shoulder.
If you do a 30, I’d seriously look at an 8 or max 8.5 twist myself if you have any inclination of shooting the really aero stuff. It’ll shoot the shorter stuff fine as well.
