Man that is a tough one. I would love to take one with my .58 Rene. And on your hunt I'd talk to the outfitter (if you're using one). Maybe you can get more info on average shot distance, terrain, etc. IMO, if you stay downwind of a bear they aren't all that difficult to get in on provided the cover is adequate and you can move quietly. You can surely get within 75 yards and that would be no problem for a .54 or .58 PRB.
On the other hand, If you're concerned about eating tag soup after the hunt the you'd best take an inline. Give you more range especially if a scope is permitted.