That's what I'm thinking, a Super Redhawk in 454 Casull should work just fine. The guy I work for during the summer has a S&W 500, what a fucking cannon.
If you get the .454, then .45 Colt ammo would be great for target shooting, and .45 Colt +P loads should be plenty powerful for most uses.
If you're really concerned about brown bears, I'd get a Browning BLR and have it re-barreled in .458-08.
You'd have to hand load for it of course.