- Welcome to the forum. Always exciting to get to design a room from scratch.
Here are a couple of questions to ask yourself...
Did you set a budget?
What is your sound control strategy? Double Drywall and Green Glue on Clips and Channel? only Double Drywall? Any sound control strategy?
HVAC - supply at the front of the room, return at the rear.
Power - Make sure you have enough power circuits to the AV Rack. target a minimum of 3x 20 amps circuits just for gear, plus a circuit for the lights.
AV Rack - Is that going to be through-wall into the mechanical space?
Front of the room I would put on the wall that has the slant on the bottom of the photo.
Screen - Acoustic Transparent screen? Use double goal post design . What size are you targeting? Large LCD instead? 4K of course... What AR are you targeting? 1.78, 2.35, 2.0
Riser, I would put an wall to wall 8 foot or larger for row 2.
Seats - sound like you are going with a 4 seats for front row? Honestly, not a fan of that. That would mean the your MLP is right on an armrest. I would prefer 3 only for front row. 4 seats in the back row would be fine.
Acoustic Treatments ? GIK, DIY?
Automation? Lutron, Insteon? etc..
Projector? JVC, Sony, Faux 4k -eshifter?
Speakers - ? DIY Sound Group Volt 6,8,10 ? Titans, Elusive 1099's? Subwoofers - minimum of 4.. DIY. UM18's? MiniMarty's? SVS, Klipsch, B&W's?
AVR? Pre/Pro? All-in-one? Monoprice HTP-1? Denon/Marantz?
These are some questions you should be thinking about as you are coming up with what you want to see and sit in when you are done.
Did you put your thinking chair in the room yet?