RE: Grizzly Rifle
Being from the rockies I know the toll that the weather, especially wet and variable weather, can have on a weapon. I would certainly take one of the stainless/synthetic combos with you and wouldn't consider the wood/blue combo. You are going to be happier with less problems/chances of problems IMO.
Caliber...I wouldn't be able to give you an experienced answer...but I would be able to give you a best guess based on what I have seen and learned.
If you are using it on a combination of the two animals I would go with the 300 mag with a 180-200 grain core lokt round. It has some seriously good spread on impact and will be a hard hit to the bears thick bones and hide. You won't get as long of a range than you do with the nosler though...so if you are expecting long range shots, don't listen to me. =) Either way, the 300 is going to be less damaging to the bou's meat and effective on the smaller inland bears.
Now if you were going after some coasties!!! That's a whole nother opinion!
~Cam