I know you have already decided what to get and it sounds like it will be fine. I want to add that I have had many 44 mag Ruger handguns and only 1 Ruger 454 in a 9.5" SRH, I currently own a 44 9.5" SRH . To say that the 454 is 50% more recoil than the same 44 mag handgun is a bit of a stretch to me. I used to shoot 300 grain cast GC bullets from my 454 at 1700 fps and in my 44 mag I shoot the same weight cast GC bullet at 1550 fps. The only difference to me is the 454 always black and blued my middle finger after 6 shots, the 44 does not. As long as you shoot a heavy bullet preferably cast with a large meplat it should get adequate penetration with maximum tissue disruption. The key is shot placement as everyone tells you and you probably already know. A 12 gauge slug at close range will not do much of anything if it travels through the animal without hitting vitals. My buddy found that out on a Black Bear last year, he did not want to damage the skull and placed the shot entering the chest and exiting the back end. 20 minutes later when they thought the bear was dead he crawled in the cave after it and found out he was wrong, putting another shot into the bear this time hitting the heart and dead bear in just a few seconds.
I use my 44 for Whitetail Deer and Black Bear Hunting, if I was to rely on it for bear protection, I would use a shorter barreled 4 - 6 inch (easier to pack) and a 330 to 340 grain cast at about the 1300 - 1400 fps, although 1200 - 1300 would be more than adequate. I would hope that after 6 shots through its chest cavity it would have changed its mind from wanting to eat me to its instinct of wanting to try to survive.
I really like the Ruger Alaskan, looks great for up close and personal, and with the time it takes for a bear to cover 50 yards that is what it will be. The 480 intrigues me, but I already have all my loading gear and cast for the 44 Mag.
Just my long winded opinion.