I'm not into the bear gun strings, for many reasons. However, as a practical matter, a G20 with an aftermarket longer barrel (I think you can do 6") and well constructed heavy solid bullets is likely to be more useable than any revolver.
A heavy load is pretty similar to the .41 Magnum (I think a lot closer than the 15% estimate above). It's 13+1, not 6. It's easier to shoot hot loads from an auto pistol. With other accessory barrels, it will do well with .40 and .357Sig (a friend has one and has done this), both of which would be cheaper to shoot for training and other purposes, like defense against humans in other settings. You are already familiar with Glocks and what will work in terms of accessories, etc. I'm not a total Glock fan, and I sure am not a fan of the .40 in general. I would surely not carry one for bears. But, the 10MM is a very different issue, and may be far more useable for your purpose than others are suggesting.
Long guns: as short as legally possible (18" barrel, which is the longest I would own; 26" OAL), for ease of handling in close. Big calibers, as have been suggested. Big visible sights, like old style express sights, or modern XS - with the big dot, IMHO. In a shotgun, a semi-auto, with slugs. There are 10 gauge semi-autos, but it would take some custom work to make one easier to handle. My understanding is that they are all big/heavy/ponderous. OTOH, I used to see 10gauge slugs advertised - 2 ounces. Not fun to shoot under any scenario I can foresee, but priceless under the conditions at issue. 45-70s with the right load; 458s, 375 H&H, etc. No really my lane, so I leave the choices to others.
