Because you are not punching holes in paper and actualy shooting game i would look at having a Sako extractor fitted opening up the boltface to magnum and going a 7mm Ultra Mag or 270 Allen MAg. They will shoot flat enough and their bigest advantage is the lack of wind drift that they exibit.
If you want to go the factory route you could possibly find a new take out 7mm ultra barrel from a sendaro i just picked you a 7mm rem mag sendaro barrel for $85US brand new. Even get a 7mm Rem Mag Sendaro barrel and have it rechambered. If going a full coultom route the 7mm Ultra or 270 Allen mag are both good propositions with the Ultra mag having a slight cost advantage with dies available cheeper off the shelf and no fireforming required. I would however have a lengthened mag box fitted and use the 195gr ULD Wildcat projectiles in the 270 or the 200gr ULD Wildcat projectiles in the 7mm ultra and get a LAwton barrel of the correct twist to corectly stabalies the projectiles.
As for the Stock talk to Joel Russo with either one of his A5L stocks of the newer one that is more varmint/long range orientated as apposed to the full tacticle A5 Style.
Also get a 20 MOA tapered rail and some quality Rings. Glen Seekins of Seekins precision
makes some very good quality mounts and bases.