First, thank you everyone for your suggestions, I think I'm going to use all of them. I've been away for the last 6 weeks (that's my wife's home country) in NZ and I'm back and ready to get this thing going. After taking into consideration of flipping the room and seating, I am convinced that's the right way to go. While poking around in that room, I came up with a few things that might make things more interesting.
I measured the cross beams and they're 14" deep. However, the back of the room where the riser and second row of seats will reside there's an extended ceiling or should I say false ceiling. Taking this out would give me 14" of added height in the rear for the riser and ATMOS speakers. It's just 2x4's with come vertical boards attached, nothing fancy. See pics below.
This picture may be hard to discern at first, but you'll see the upper beams where the wire's are and then the false ceiling 2x4's below.
This next image show's the other area's without the false ceiling (I don't know if that's what you'd call it).
The next section is where there's some dead space I was going to use for the equipment. The space is a bit tight to put a rack in, so I was planning on moving, the non-supporting, wall 6 inches into the room. I loose a little space on the sides, but not much and that enables me to double sheetrock on both sides.
Where the thermostat and light switch are located is where I plan to put the rack. It won't be facing into the room.
With that said, I plan to put in a wall and interior door for sound proofing. So this wall that I plan to bring out 6 inches will extend the whole length of that room. Here's what the space looks like currently.
Lastly, is this what they call a decoupled wall?
I plan to remove some, if not all, of the insulation to use Roxul stone wool insulation. I've heard it's better for soundproofing etc. I'll post the other sound proofing measures I plan to take sometime this week. Soundproofing is important. Our house is steel frame and vibrations tend to travel further than expected. This never happened in another steel framed house we owned, so I'm a bit perplexed.
I know I've said a lot in this post, but I really would appreciate some constructive feedback. Any suggestions are welcome.