For $3700 I'd go the full custom route. The Weatherbys are nice, and very pretty, but they still won't hold a candle to a truly professionally built custom gun with a Rem 700 action as the basis for the rifle. I'd listen to Ridge Runner, he know what he's talking about. If it were me, and I had a lot of money to spend, I'd be looking at a custom M700 built by Kirby Allen in 7mm Allen Mag or .338 Edge. You want to talk about a long range rig, there it is. From what I gather, they'll shoot the wings of a gnat at 200 yards and both cartridges are legit 1k+ yard shooters.
Mike