I am currently doing a build just about identical to this for a buddy right now also. All you really need is the magnum bolt face. The bolt stop is easily changed out and so are the mags. I found a cheap stainless T3 in 7 Rem mag that will be getting reconfigured to the 6.5PRC but I am trying it...
The stock did require a fair bit of inletting but fits the Proof Carbon pipe perfectly in my opinion. Also it is fully bedded and free floated. Tikkas also come free floated from factory.