speaker selectors
Don't know if you got a reply to this yet..
Niles makes a couple of speaker selectors.
I'm running a SSVC6 - it handles 6 pair of speakers, and allows me to set the individual volume level for each pair.. the inside circuitry makes your amp think only 1 pair of speakers is attached (blanaces the ohms)
There's models available without the volume control also.. I opted for the volume one becuase I run outside speakers in the summer.. and I like them a bit louder.
There's also another mfg that had a unit that accepts 2 sources, so the speakers in one room can listen to something diff than the speakers in another room.
Go onto ebay and search on "speaker Selector".. it should giveyou the niles units and the other mfg.. mine ran around $200