I would go with a 338/378 because it will fit your action
with out any alterations.
If you want to keep the stock go with the largest barrel
you can with out removing to much stock and a muzzel
break because there will be a lot of recoil.
I dont use muzzle breaks ,instead I like heaver barrels like
#7,s or #8,s but 30" is about as long as you can use with
out being muzzel heavy.
Heavy barrels do a good job of reducing recoil .
Example!! A 30/378 shooting 200 gr bullets@ 3200 ft/sec
8.5 lb rifle produces 52.0 ft/lbs of recoil and 19.8 ft/sec recoil vel.
12.5 lb rifle is 35.4 ft/lbs of recoil and 13.5 ft/sec recoil velocity.
A break will bring it down to about the same level but you have to
contend with the noise.
As far as stocks I realy like laminates, they add a little weight
but most is in the butt stock helping the balance of heavy/long
If the 338/378 is a little to much then the 30/378 is a good choice
with the same barrel and stock combo.
J E CUSTOM