OK. I have some progress to report. Ted, sorry for the delay in responding to your request. I was busy with electrical, painting, etc. and did not visit AVS for a while.
Most of last year I was busy with permits, getting framing, electrical, drywall, painting, etc. done. I have posted some pictures to share as well. Just a few modifications since I posted my floor plan: I decided to wall-in the curved space and use that area for my equipment rack. This serves two purposes: makes it easier to deal with acoustics - curved walls will present a focusing lens for sound. This was suggested to me by Auralex. The rack in a separate room also allows noise/heat to be in a different room.
My screen wall is now 215" wide and 102" high. I plan on a 2.40 screen that is 65" high (acoustically transparent). Researching materials right now. Leaning towards Seymour Center Stage XD.
I used whisper clips and channels/green glue/double drywall (5/8") and double studs as suggested by the Soundproofing Company on all the walls+ceiling. I got good prices from them. John Hile was a great help throughout the process. No 'holes' for lights in the ceiling. 'Pink stuff' insulation from Home Depot in the walls and ceiling.
Dennis Erskine suggested that I use bar type registers (diffusers pointed downwards) for supply and return and have them installed near the ceiling. I used 4 4x48 bar type registers (see photo). Supply is near the screen and returns are at the back wall. You can see them in the pictures. Two for supply and two for return. I used insulated 8" flex ducts for supply and return. My HVAC contractor did the final design according to my specs for max. air velocity at the registers. I have it installed so that it can be easily upgraded to a separate zone in the future if needed. The HVAC contractor calculated a required air flow of 340 CFM based on a 10 person occupancy and equipment.
I did all the electrical+low voltage myself. I am including a picture of the low-voltage rough-in for my rack which will be in a utility space. I am also including a picture of the adjacent rec room that shows the door (on the left) to the theater.
I am finishing the rest of the basement as well (all told, 1800 sq. ft+). So, progress is slow. Now, my goal is to keep the rest of the basement moving forward so that I can get it inspected. I want to get the entire project to a point that it passes final inspection. Screen walls, speaker columns, etc. are not necessary for the inspection.