Is it not just a long action, but a long action magnun in 338WM. They are different.
The 338WM is not just a medium range big game cartridge. It is well suited for long range as well.
Very expensive though for a prairie dog.
I would stay away from a break.. they are usually detrimental to accuracy. Don't believe me? Check out any precision competition.. no breaks to be found except on BIG calibers.
If you want a stock, Fred at Sharp Shooter Supply can make any of his stocks for a DBM. http://www.sharpshootersupply.com/
Prices are reasonable. They also have a bunch of accessories like larger bolt handles and heavier recoil lugs. The recoil lug is a must IMHO for a precision rig.