My theater room is 187" by 257 3/4 inches long. No windows to room but I had to frame utility closet in back of theater for mechanicals which decreased length of room to 21.5 feet. I have a sofit covering HVAC and steel I beam towards the back of my space that drops down to 7'7" the rest of the ceiling is slightly over 9". I guess I need some help with spacing and layout. I need to leave room to walk into utility room, door will swing into utility room. I assume I need to sit back 11-12' from screen. I want a riser and a sitting bar behind riser for a few seats under sofit.