Thanks for the responses so far.
I guess my main concern though, is whether or not the I need the 9" driver provided by the UIW 94/A, or if I can get away with the 6.5" in the UIW 64/A.
With the open concept + the height of the room (13.5'), I'm worried that I won't get the "effect" I am looking for. The Mythos 2/3, supercube I, and pioneer elite VSX-94TXH sounded awesome together - I just want to do them justice with the surround sound speakers.