Though perhaps too late for the op (and most of us who are unable to build a room from the ground up), the wall system offered by Acoustic Sciences Corp. is incredible. It wasn’t until I heard a room (that of Audiogon member folkfreak) built using the ASC products (brackets to suspend the sheet rock from the wall and ceiling studs, Wall Damp constrained layer damping sheets between two layers of sheet rock, other stuff) that I became aware of how much noise walls add to the sound produced by loudspeakers.
The walls in folkfreak’s room, when rapped with my knuckles, produced a completely-damped "click", rather than a resonant "thonk". Try rapping a wall in your room, then do so with your other hand pushing hard against it. Huge difference! The room’s floor is poured concrete.
Folkfreak also had ASC soffits running along all the wall/ceiling intersections, acoustic panels (presumably filled with Owens Corning 703) alternating with blank wall (see his system in the Virtuals), and a vast number of Synergistic Research products. The combined effect of all the about was a startling quietness I had never before heard in a room and from a hi-fi. I could hear no evidence of the room itself, only the sound produced by the Magico loudspeakers (and the sources and amplification---all of superior quality, of course). The system itself was also dead quiet---no hum, no buzzes, no hiss, no noise of any kind "riding" on the music. I don’t know how much of that quiet can be attributed to the RS products; perhaps @folkfreak would care to comment.