Smarthome isn't the only source for these items, but it's a good place to shop.

Up to 8 speakers from 1 amp, one source: [Link: smarthome.com]

Switcher for up to 6 speakers, one source: [Link: smarthome.com]

Volume control, 2, 4, or 6 spkrs, 2 sources: [Link: smarthome.com]

Amp for six pairs of speakers, six sources: [Link: smarthome.com]

Need separate amps?: [Link: smarthome.com]

These items and other stuff: [Link: smarthome.com]

Larry
www.fineelectricco.com