7mm08 is the first cartridge that's comes to mind. If it was me I wouldn't be looking to "go heavy" to reduce recoil. I'd look at a lighter recoiling cartridge capable of doing the job. With a 12.5" LOP a couple of "factory" rifles come to mind. Ruger Compact,Tikka compact.Savage Lady Hunter (no sure on the LOP) Winchester Model 70 compact (LOP is 13") I think all rifles mentioned come in 7-08, and depend on which scope you pick should come in betwwen #7 1/2-#8. I know you said "build" but just a different option.