You might consider engaging the services of a professional acoustician, so that your efforts are directed by someone who really knows what they're doing. This is the sort of project where intelligent choices made early on are of great value, but mistakes made early on may well be prohibitively expensive to later correct. My recommendation would be Jeff Hedback, of Hedback Designed Acoustics - he's a multiple-award-winning studio designer who still does work in home audio at very reasonable rates.
Duke
Duke