Here's my room layout:
You can see roughly where the IBs are going and using the room at the top of the page for the rear of the drivers. I've changed the room a little so that I can get the IBs a little farther apart and more ideally placed relative to my mains.
I have rebuilt the entire "front" wall and that little closet that is home to my audio gear. This also makes that back room a little larger since I got rid of the other closet back there, and moved my gear closet further off to the side in my main room. It's tough to describe, but as soon as I committed to a 2x10 wall for structural reasons, the gloves came off (or went on) to go all out once and for all. The 2x10 wall allows me also to completely conceal and protect the drivers.
Since I'm doing an array, I am doing everything possible to reduce structural compliance and increase the mass in the wall. Each array structure will weight in excess of 600 lbs easy. I am adding eight 6' concrete lintels to the sides of the arrays inside the double layer 5/8" drywall. There will be a lot of mass, and completely invisible.
The concrete Lintels: