Re: the best .308 set up?
I endorse a heavy-barreled AR-10 (T) as a Best .308 rifle.
Better than sniper/tactical rigged bolt rifle, better than Jeff Cooper's Steyr scout rifle. Bolt rifles are quality items and rugged. I've owned a Steyr Pro M in the 80s and took deer with it, a .30-06; nice but...
Scout scope is not worthwhile, unless it is all you have. Scout rig is all built to Cooper's spec and he simply did not live long enough or was in poor health when the AR-10 was returned to the civilian lineup. He talks ad nauseum about "riflery" in To Ride, Shoot Straight and Tell The Truth, which I read regularly; never did read his On Rifles or whatever his rifle manifesto was called.
AR-10 has all his carbine could ever offer, but has built-in picatinny rail, easy gunsmithing, superb Geiselle trigger, up to a 25rd magazine, and more options for scopes, sights, and barrels than any other .308 semi platform. Much better than M1a which back then he felt had best trigger potential.
AR-10 will compete at the range with any tactical .308win bolt rifle. There is no effective velocity loss due to gas cycling, but there is less felt recoil.
10, 20, or 25rds available and overall length of about 37 - 42" makes the AR more able to engage multiple targets. Load your rifle with 180gr premium bullets if you want to hunt with it.
If you just want a bolt, or are on a budget for your "best" rifle; I'd go with a Winchester 70 action, custom barrel, H-S Precision or better custom stock, and probably Jeff's CS Precision bottom system for AICS magazines, with Near Mfg picatinny base.