Where did I get you wanted an 18" barrel? Oh well if going with a 14.5" you will have less dwell time so that should equal out pressure when you install the can. I'd tell them you are going to run suppressed and see what they say.
My Noveske had the intermediate gas at 18" (SPR) and it ran great. Most now have gone to rifle gas when 18" or above. At least that was the trend a year ago.
I'd stick with the Krieger barrel and a 14.5" mid length gas should be pretty smooth. I think the mid-weight at .850 under the hand guard, .750 gas block and .700 in front of it would make for a pleasant carrying carbine with little zero shift when hanging the can on it. Sounds like a good project.
Noveske does build 14.5" SS match barrels that are gassed for suppressed use as well. Might take a look at least for ideas...
