Clifford,
I like Glenn's layout idea a lot. I would also move towards making the control room larger!! Trust me (us)... anyway, working with the limitations you listed on dimensions, I would still recommend a rectangular shell to start with. Geometry (such as Glenn shows) can be built into the treatments (acoustic finishes).
If you were to work in the smaller alcove for the control room some possible dimensions that work are: 11'-10" x 9'-11" x 8'-4 1/2"...
If you were to consider a larger control room such as in Glenn's idea then it looks like 13'-0" X 11'-2 1/2" X 8'-6" is the best option that fits (after a quick look that is). It's not that much a bigger room, but I do like Glenn's layout ergonomically.
Interestingly, the modal response if 'flatter' in the smaller room, but there are a few modes lower than 36Hz in the larger room...
You've got a lot of good suggestions and information now. I think it's time to look it all over and make some decisions as to how you want to move ahead. Let's keep the thread open.... this is a fun one (for me).