I'm generally against comped pistols. They have a tendency to spray powder all over the place and they kill your night vision. If it is for use as a range/race gun that will be fire during the day, go for it. If not, save the money.
It seems to me that Glock makes ported barrels an option, you might ask your local dealer if they can get you a barrel and a slide.
I have carried a Glock 23c as a duty weapon for 4 years. I never noticed any powder/ residue blow out, even with "wrist on hip" drills. As far as hindering night vision, I find a flashlight illuminating the target has a much more significant impact on that than increased muzzle flash. Just my input.