Thanks, It looks like I am gonna go with the AudioSource Amp.
I do have one more question. None of my speakers are wired with volume controls. I know that there is a volume knob on the AudioSource amp, but the amp will be in a closet. Is it possible to add a volume control for the entire zone-2? I don't need volume controls on these speakers for the impedance matching because that is being handled by the speaker-selector box. But a master volume control knob for zone-2 would be nice.