The 125 gr 357 is pretty much the best manstopper there is. But, if you are concerned about large carnivores, the 357 may not be the best, even when loaded with heavier bullets. I am a 38/357 guy myself, but the 357 is a very hard cartridge to shoot well. I seldom load my guns with them anymore. I think like Kieth says, the sound has a lot to do with it.
But, since you choose the 44, a good choice in my opinion, by all means get some tools and start reloading for it. The 44 is a good gun, but only if you shoot it enough to be good too. Don't let high priced ammunition prevent you from being a good shooter.