My current Glock is set up in .40 S&W, .357 SIG, 9mm, and .22 LR.
For practice, I shoot mostly .22 LR,
but I enjoy the "WHUMP" from a .357 SIG round more than I do the .40 S&W or the 9mm.
I would recommend an Aftermarket RIFLED barrel for your Glock conversion. The chamber will be tighter than the factory Glock barrel, with better case support. I've used Barsto, IGB, LW, and Storm Lake barrels, and they all shoot pretty good for accuracy. But every individual pistol will have it's own preference for which brand shoots the best.
Right now, my G35 length 9mm IGB barrel shoots exceptionally well with 9mm Win HP,
better than with any other caliber or any other brand barrel ...
in that particular Glock.
The longer G35 length [ 5.3" ] SS barrels DO increase the velocity and power significantly, but don't balance quite as well for me as a genuine G35, with the loger slide and sight radius.
PS
I've got a SPARE factory Glock .357 SIG barrel for a G22 FOR SALE in the EE.