IDK if they make a pre fabricated stealthbox for a 12" off hand. But you could always have one made at a shop. All they would have to do is make a fiberglass mold of the jack storage location.
The recommended airspace for a sealed enclosure is .8 cubic ft. after sub displacement. An enclosure of about 1.2 cubic ft. would be about right for the "stealthbox" for this sub. That size is including sub displacement in the box
