https://www.shotgunheatshield.com/mossberg-shockwave-remington-tac-14-shields/
Email him and tell him you are looking for a 14" Mossberg with ghost ring sight cut out on the heat shield. He started making them and he ships to Canada, Great guy to deal with.
They do pull away from the front blade as you tighten them, But with plastic that's the name of the game.
I was one of the first for the 14" prototype before he made one with cuts, So I had to cut my own slot for the front sight. The new ones with the cut are single front band, Not dual. I havnt had time to put it on yet, But I gave my buddy a hand when he put his on.
Original and New style: