The 550's are quite nice. SS trigger is nifty. For your purposes, I'd go with the heavier barreled varmint. I'd not be concerned with a DM, and the .308 is a great caliber. What scopes are your considering? The Zeiss Conquests with the Rapid Z reticles are dandy. Personally, I like the Z 600 but the 800 is also doable. Good luck with your selection.