Bbates, you asked a lot questions in that post on a wide range of rifle topics. I think a lot of them will be answered once you shoot more matches.
Why do you think your 16" barrel needs replaced? What is its current accuracy? Have you tried it with match ammo?
For rifles, my suggestion would be to throw the Razor on your 16" gun and go shoot. Make sure your holdovers are figured out at the further distances. You can sort out what to do with the second build as you see the courses of fire, distances engaged, etc. I will say that a lightened bolt and adjustable gas block are almost a must for a game rifle.
Ammo is in the same boat. If you are committed to reloading I would work up a few loads and see what shoots the best. Whatever suggestions the powder and bullet makers make would be a good start.