Re: .308 win
Unfortunately your rifle makes that decision, we have all got favorites based on range and hunting performance but there is no way to determine how that brand might shoot in your rifle. Bottom line is that most ammo loaded today is very good. One suggestion is Winchester Supreme, seems to shoot very well every time I use it. You might be wise to try several boxes of different brands and shoot them on the range - 165 grain bullets are excellent in the .308 and there are some dandies being loaded by the factories. The hot bullets these days are bonded plastic-tipped boat-tails such as the Swift Scirocco (from Remington), Hornady's Interbond available in their Light Magnum loads and Nosler's Accubond which is being loaded by Winchester and also Federal I believe.
Good luck with your shooting, you have selected one of the nicest rifles available today - I am confident that you will be saticefied with the Sako 75.
You next decision is mounts and optics - I like the Warne mounts made for Sako's over their mounts. If you want to shoot fairly long with that rifle your considerations are a rangefinder reticle or really good turrets (or both). Lots of great choices, spend some money on your scope and you will never regret it.