Well I am trying to invision your room but with 20 foot ceilings and a balcony, your room has got to be at least 30 feet long to do what you want... You cant just stick a balcony, much less a substantial one in a room best suited to "home theater" appications. What your describing involves MUCH more than your ordinary 7.2 speaker system. Once you get into bigger rooms, you start talking about speaker arrays for each channel with 2 maybe even 3 or 4 speakers per surround channel depending on the size of the room. Ive done a room with 2 speakers for each surround channel, but once you get into systems bigger than that your talking some serious "commercial theater" audio gear that works with time alignment and room acoustics.
Just my opinion
Mike

Oh yeah, lets not forget video... Expect to pay atleast 20K for a good projector that will handle a giant screen, check out Digital Projection