I think Ruark summed things up nicely. Ultimately, its all your decision, and a decision best made on personal experience rather than a consensus of others.
I wouldnt get to caught up in the caliber debates. These days, most of the premium ammo in the usually accepted "full size" calibers are pretty close. I seriously doubt a similar hit with any of them would give a different result. Now shooting them can be different and in some cases, a challenge, depending on the caliber/gun choice. Getting those hits may be easier with one than another.
There was a time when I was of the thought that only a .45acp would get it done, and if you couldnt solve "any" problem with 7 or 8 rounds, it wasnt getting done. Im a little older and wiser now.
These days, Ill take as many rounds as I can reasonably get in the gun, and the .45's have been riding in the safe, and haent seen a holster for quite awhile now. My J frames dont see the light much anymore either.
Just a personal note on 357SIG. Ive had a number of guns that were chambered in it, and its the round that started me on the path away from the .45acp. I liked the near 357mag power in a package about the size of a 9mm, and a capacity that was close to it too. After living with it for a little while, a little more research, and with changes in ammo costs, I came to the conclusion that I'd be better served with a 9mm.
For the difference in the cost of ammo between them, both factory and reloads, I can shoot a lot more, and 9mm +P+ is basically the same thing, power wise, as the 357SIG, so I have the best of both worlds.