Elkkillinfull, if you havent already decided on a brake, may i recommend the assassin muzzle brake
from jecustom.com? IMO his brakes are the best on the market as far as recoil reduction. I am also considering rebarreling a gun to a 338 Lapua and will be using this brake, it should bring recoil down to the 15-18 ft lbs range with a 300 grain bullet, that is just below the level of a 7mm rem mag. And if you are looking for a barrel, bugholes.com has some bartleins in stock at the moment.