I have confirmed the LAPCO tips will thread on to Stella barrels. Keep in mind with the 14" Stella tip you are measuring out at about 14 1/8" and with the LAPCO Phantom mock flash tip it brings you up to 15 3/4" because it doesn't slip back over the barrel tip as much like the Arrow heads do.
New rig for this year - Empire Mini CS, Lurker Bolt, Lurker Poppet, Stella Barrel, Spire 260, and a Ninja Superlight Tank with Pro-reg V2