HD gun vs camp gun

I'm new here and have some questions...

I have read through all the archives here and learned an awful lot. I am looking for my first shotgun, for both home defense and as a camp gun. I am leaning toward the Benelli Nova Tactical because of its design, and I like the lightness, durability and low maintenance of modern "plastic" guns. I carry a Glock 23 routinely and also own a Series 80 Gold Cup .45 ACP, but feel the need for a lot more power when camping with my family in the boonies at the lower end of the food chain.

I often camp in primitive spots, and plan on spending a good bit of time in western Montana and northern Idaho in grizzly country. Obviously the gun would have to be packed away inside the National Parks, but I would keep it handy at all other times. Can anyone comment on the suitability of short barrelled HD shotguns in an encounter with a (very large!) pissed-off bear?

What load would you recommend for bear? Slug or buckshot?

Thanks for any other advice or comments about camp guns vs HD guns.

John