Hiya Will,
If you are stuck with Kanada's Stoopid rules about handguns, you are going to be kinda limited.
The 12 gauge shotgun with both slugs and shot in bear country is a good idea. If you could carry a handgun as well a .22 revolver, specifically a Ruger Super Single Six in stainless steel, with both a .22 Long Rifle and .22 Win Mag Rimfire cylinder would be great for small game and economy. The .22 WMRF loaded with solids makes a pretty good impression even on big brutes (four legged type) with head (end of nose or eyeball shots) or neck/spine shots. With Magnum Hollow Points you can add defense against two legged big brutes and add chest (heart, lung and thoracic spine) shots to your repertoire to the above list.
If you are interested in centerfire rifles instead of the scattergun, I would start with the Marlin or Puma stainless leverguns. For just flat out easy shooting and versatility the .357 Magnum is great, but light for big bears, although not a blunt spear by any means, especially with 180+ grain hardcast bullets at high velocity. The .44 Magnum is more power and more recoil, but with .44 Specials for small edible game, it does pretty good on both ends, with a lot more authority on the top end for serious stompin’ power. Above these, the .454 Casull in the Puma Model 1892 is kinda the same, .45 Colt squib loads for lightweight tasty critters with little meat damage and +P .45 Colt on up to the full house .454 Casull loadings for big bruiser bruins. The Puma is also available in a 16 inch barreled carbine and that makes it just about as handy as a pistol. Just be aware that as you change loads you will be changing your bullet impact point as well. Handloading can make this less of a problem, as you can tailor your loads to your needs and your guns sights (sometimes). With factory ammo, you just have to learn where your gun shoots with a couple different loads. Keep it simple if you go this route, don’t go more than two different loadings, it’ll give ya headaches.
There are others (.30-30, .45-70, .450 Marlin, .475 Linebaugh / .480 Ruger, bolt actions, autoloaders, .308, .30-06, .338 WinMag, .375 H&H, .458 Winchester, just to name a measly few) and if that suits you, go for it. Part of gun ownership should be that you get to own and shoot a firearm that you enjoy and like. Something that I might love to death may be a complete Ho-Hum to you, and what gets your metabolism going may not trip my trigger. So find something you LIKE! Just remember, no matter how big a gun you shoot, if you miss, it doesn’t matter one bit what’s stamped on the barrel. A .416 Rigby is worth less than a .22 if the first is a miss and the other goes down the optic nerve canal.
You can carry extra rounds for any of these shootin’ irons in buttcuffs. The shotgun can carry 5 or 6 extra, the lever carbines up to 18 or 20, if you double stack the rounds butt to butt, centered inside the cuff’s 9 (most common) or 10 elastic sleeves.
Ideally, I would go with a Levergun / Revolver combo in the same caliber (.45 Colt / .454 Casull for my personal choice) and then a .22 pistol backup. The big bore sixgun may not get a lot of use in the hunting or defense department versus the carbine, but I don’t live in Kanada and am free to carry a sidearm and prefer it that way. I also don’t much care for shotguns. See what I mean about shooting what you LIKE!
Best of luck to you. Shoot early, shoot straight and shoot often.
Conquer yourself first, all else will follow.
KJM