If you have any intention to use a revolver for defensive purposes, go with a DA/SA. Single action only revolvers for defensive purposes have been obsolete since about 1885-1890 with the invention of the swing out cylinder and modern DA/SA revolvers. Not only do you have to cock the hammer with each shot, you're going to have to load the gun like a Colt SAA or a M1895 Nagant - poke out each case one at a time with the rod or a stick and reload one at a time through the loading gate. Assuming you get a traditional SAO revolver like a SAA clone. Also assuming that you're getting a modern gun that's drop safe and that you won't have to only load five in because you can't leave the hammer down on a loaded chamber.
Let me put it this way: people going into combat have favored DA/SA revolvers over SAO revolvers since the Crimean War. If a bear is attacking you, you're going to squeeze the trigger as fast as possible and you will want follow up shots as fast as possible. You're not going to want to sit there and cock the hammer between each shot and then do a Nagant-speed reload.
I lived in Grafton County, NH, where you'll run into black bears fairly often, and if I was going to buy a specific woods gun for New England, I'd buy a Glock 40 MOS and mount a RMR on it.
GLOCK 40 Gen4 MOS - G40 Gen4 MOS - Modular Optic System
If you live in Mass, a G20 would work the same and you'd just have to have the slide milled. This isn't Alaska or Montana where you'll need a .44 Magnum for bears.