Bell and Carlson Medalist. Relatively inexpensive, bedding block, rigid etc. Makes a huge difference in the way the gun feels and shoots. The SPS stock are crap, I have two of them and can't give them away, my boys made toys out of them. You can spend a ton more on a stock and certainly get more features but the BC is the least expensive option to get close.
Both rifles that I have used them on are sub 1/2" MOA guns, I think I have about $1500.00/per in the guns, not $6K.