9 channels is crazy, think of the amps, cables , yikes !
Not to mention you would need a HUGE room to even think about it. But as to the Firewire , unless you are having massive bass mangement issues, which I personally do not, IMO its crazy to have to upgrade 2 components, especially if your already happy with your front end and DAC. The Firewire connection would have to provide a "significant" sonic advantage for me to consider it. I could be wrong, but my gut reaction says it wont.