Looking for opinions on the electronics for a whole home audio solution.

Father-in-law has a house wired with 7 zones, two speakers and volume controls in each room. Everything goes back to a wiring closet. Not sure if the volume controls are impendance matching.

The music is mainly for background music, so I don't need a high-powered solution. Don't need any controls in the rooms. just need decent audio.

I was thinking I could just get a moderate stereo receiver with an A and B output. Pipe the A output to a 6 zone speaker selector and the B output to the 7th zone.

Any thoughts if that would be a good enough setup? Sound quality? Someone mentioned that this option might create more stress on the receiver.

Any idea if a simple speaker block will do the trick? As long as the receiver supports 100-200 watts?

And will either the speaker selector or the block work fine with the volume controls if they are not impedance matched or does having impedance matched controls help?

Other option was to grab a separate amplifier, but those seemed a little expensive for my application.

Four speakers, two in series times two in parallel, will have the same impedance as a single speaker. You could even put three in series, times two in parallel, for a higher impedance than a single speaker; that would allow you to drive six speakers. However, you wouldn't necessarily get independent volume control if that's the set-up.
For independent volume control, you really want a distribution (multi-channel) amplifier. It doesn't have to be all that terribly expensive, perhaps a few hundred if found used somewhere?
Also check the impedance of the speakers; for example if they are "70 V" type speakers, they need a separate set-up than a regular home amp.

Some google links (just random links; haven't use these particular brands):
Active distribution amplifier, around $700. (http://www.dagexpress.com/incEngine/?product=1030198977&affiliate=605)
Passive splitter/impedance matching panel, around $150 (plugs into a regular stereo amp) (http://www.smarthome.com/8267.html)