I think that you would want something other than just a stereo receiver if you want to power five pairs of speakers at one time. Hooking those up in parallel to a stereo receiver would likely change the impedance that the receiver experiences to be out of the specs for the receiver.
However, combining a stereo receiver with one or more external amps could achieve that easily.
There are a few people on the forum who have whole-house audio systems, and hopefully they will chime in here. I don't know if any of them are online right now, though.