Will probably seem off base from a stricken handcannon shooter who preferred the biggest/badest on his TC's, but...
At those short ranges its not a matter of enough gun or how flat it'll shoot as much as what you can comfortably shoot with the most confidence to make a good first shot with a handgun IMO. While your bottleneck coices have way more than enough power and flat trajectory even in a short tube, they are just not needed for this scenerio. So why deal with their issues if you don't need to? A 44MAG is more than enough and flat enough at 100 yards, will bust brush better and is more pleasant to shoot than a 454 Casull.
As for the "I" stuff... I killed more than my fair share of big western mulies out to well past those ranges with 44MAG in my open sighted single actions (and a few at least as far as up to your short range with 357MAG, 41MAG, 45 Colt SA's). By design an Encore will do more than the SA's in all of these cartridges. An 8"-10" 44MAG would be my choice in your shoes, easier to carry and use in a tree stand than a 15", and I'd put a bright 1X, 2X or 1-4X scope on it if not just using open sights. The weight of the Encore and scope will have a taming effect on even hot 44MAG loads over the SA's as well, making it a pussy cat to shoot and so easier to master.
FWIW-YMMV