Big Blue, you can't go wrong going with a Ruger Blackhawk in 45LC to go with your carbine. I recommend a blue 4 5/8. Blue instead of stainless because the blue gun is partly alloy and lighter. 4 5/8 because it carries better. I'm old, and I've been up and down the handgun ladder so many times I got dizzy. I've had 'em all, in all the barrel lengths. 191l models, Colt single actions, S&W revolvers and autos in every configuration and caliber, but I came back to a plain ol' Blackhawk in 45LC. Since the .44 Magnum came out, the argument between that caliber and 45LC has been visited by gun writers and shooters, and still there's soldiers in both camps. There are those who say the LC brass is too weak for hot loads--they say if you want a magnum, get a .44. I say, if you want a non-magnum that will kill anything you want to shoot at, and which can be loaded to exceed any 44 round, get a 45LC. My 4 5/8 shoots 300 grn. LFP's under a healthy dose of 2400 into less than 1.25 inches at 25 yards. The magnum blast is absent, and recoil allows a quick second shot if you need it, which ain't likely. Custom handguns galore are available. You can get exotic calibers, trigger jobs, barrel porting, scopes and whatever one might imagine, but a Ruger Blackhawk out of the box is still king of the hill for a hunter's second gun.
And another thing: If your handgun is on your hip and your rifle is in your hand, why the heck would you want to carry around an overly bulky tricked-out handgun. The handgun is to compliment your rifle, to be on your person when the rifle is out of reach, to be a non-burden, but still be potent and deadly.
Get a short-barrel Blackhawk.