I've got a big show in my area next week and plan on looking for a 9mm AR. I can't have a suppressed gun in Missouri, but like the look of the shorter handguard/barrel. Would I be better off looking for a 11 1/2" barrel and permanently attaching a 5 1/2" compensator, or getting a 16" barrel and attaching a fake can? In general, who makes the higher quality 9mm AR's.
Could I legally buy a pistol and permanently attach a muzzle device to get it to 16" and install a stock without additional SBR/AOW paper work?
Sorry if this is redundant, I've read a lot of posts and couldn't find the answers I was looking for-at this point, educated advice would be great. (Darksider looking for an AR so I'm not up on anything concerning this version yet).

I'm giving myself 1 bump, last chance to keep me from running back to the Dark Side

free bump since I'm interested in a 9mm AR build