That solution works pretty well with a .22 can. Tac Sol sells those, but your overall length with suppressor mounted is longer because you need 16” w/o suppressor, but enough of the suppressor protruding to grasp.
A shroud big enough for a .30 can would be rather large. No way to tuck that into a handguard like you can with a .22 can + shroud.
I’d go for the second stamp. Just shoot it as a pistol while you wait. Then you could swap other short uppers onto it as desired, and no issues with never being able to change handguards or gas blocks as you would with a pinned shroud.