Welcome to the addiction! Your choice in rifle will be a good one. The nice thing with that rifle is that you can turn the muzzle break off and on. So when you are on the bench it can be on for shooting comfort. When your in the field, you can turn it off so that you are not busting your ears. As far as ammo is concerned, Federal Premium Gold Match in a 168grn or 175 grain will do all you need it to. The other option is the Black Hills Match ammo in the same weight bullets. Good stuff if you can get a hold of it.
As far as rifles, there are the varmint models, and the predator models. You can't really go wrong with the one that you have chosen. From what I have read they are very capable long range rifles from the beginning. Hope this helped out.
Tank