So the tube is the same for the stock, your scope mount must match the scope tube (I.e. If the main body is 30mm, 1", 34mm, whatever... Pick the scope first and then match) didn't know they offered a wide but it's a great trigger either way, headspace isn't hard and Rainier will do it for you too if you mail them your bolt.
I suggest Heavybuffers.com buffer and spring, great product, I run them in all my rifles. You will need a muzzle device and gas block. Otherwise I think your list is pretty complete.