I have a recent vintage Kimber Montana 280AI and really like it. It's been fine out of the box. It's my only light big game rifle and I like that option in the mountains. I really like the stock and trigger.
Another point, you don't need a 375 for moose, they go down pretty easy if hit well. I wouldn't hesitate to use the cartridge on moose, just pointing out that is in no way needed.
Bighorn TL3's are great actions but not needed for the type of use a 375 Ruger is best suited for. You don't need quarter MOA accuracy for a relatively short range thumper (compared to many rifle cartridges discussed on this site). If this is to be a typical hunting rifle, any of the M77...
Starting to contemplate a 300 PRC. Knowing that is fast twist is going to be needed, who do recommend that is making a 1-8 or 1-8.5 in .30. Did a bit of looking around on the net and didn't find much available, at least in stock.
The Fieldcrafts sound like a good bet. I picked up a Kimber Montana last year and have been very happy with it. Really like the stock and trigger and it's very accurate. Mine is a 280AI. If I wasn't hearing of the dropoff in QC I'd be interested in a NULA too, but not willing to take that...
Sent. One thing to keep in mind, if thinking further down the road, GAP gives a good deal on re-barrels for rifles they built. They currently show $290 for labor, to re-barrel.