Re: Which remington 700?
McNasty as mentioned above, it might get you a lot further on this site, if you refrain from using the term sniper rifle build and use something like precision rifle build. With regards to your original question, it would really be a great place to start if you picked up a Remington 700 5R in 300 win mag, if you look around they are available with both a 26 inch barrel and a threaded 24 inch barrel and if you plan to do as much shooting as you suggest, then a brake will ease the pain with the 300. As for going with a Remington 700 PSS in 300, the cost isn't really that much more, but I think many will agree that the 5R barrels are providing excellent accuracy out of the box, a suggested starting load might be 76 grains of H-100 over the 208 Amax. Also with regards to the AICS stock, although an excellent product its not for everyone, I suggest getting some time behind one before you purchase.