I run a Vortex Strikefire on my AR and she runs perfectly. (Knock on wood) however my lil' ol 5.56mm does not have the same impact as a 12ga. I see no problem in the Vortex holding up on her, they are nice solid units.
As for the long barrel on the website she is shown with the barrel extension installed which the custom comes with. The photo we took above shows no extensions installed. (Easier to keep them in the trench coat)
Tyson.