A few more thoughts and design considerations that you may not have run across...
When specifying A/C service, be prepared for running the system to cool the room pretty much year round (where are you ?). Each person produces heat more-or-less like a 100W bulb, plus the 250 or 300 watts in the projector, plus any other electronics or amps that might be in the room, or any lights left on (not generally recommended), so the room will warm quicker than you expect. There are a number of build threads where the details have been hashed out, but some guidelines include trying to turn over or replace the air in the room 6 times per hour - that's a lot. And as J_P_A said, keep the vent velocity down - shoot for 250 fpm or less to keep them quiet - that's much lower than normal.
Supporting both the idea of cooling the room and minimizing extraneous light, you might consider putting the AV equipment in a closet or rack outside the theater. Often, closets are designed so that the face of the equipment is accessible from within the theater to load discs or adjust settings, while the rear is outside and ventilated elsewhere. Equipment racks require their own considerations, but generally provide enough advantages to make it worthwhile.
You might also look into an acoustically transparent screen or the importance of masking systems or maybe constant image height with or without an anamorphic lens ("a-lens"). If you haven't read through a few build threads, it's definitely worthwhile to spend a few hours (days) browsing and seeking inspiration. If you check the sticky threads at the top of the dedicated theater construction forum, you'll see the index of "show me" threads, which are great collections of theaters you can search for ideas that suit your preferences.
Sometimes it's tough for us (me) to make recommendations without knowing what you like and expect. With such a blank canvas there are so many options (not to mention it's taken me about three or four years of reading this forum to accumulate the "knowledge" that I have), I could design the space for me but not necessarily for you.