First off, please don't double post. Anyway, the setup depends on your goals. If you're just running the speakers for ambient music (IE party setting), then it would be best to run the whole system in mono. Otherwise, you're going to have some speakers running only left, others only right. As for what you need to drive them, a high-quality amp designed for that application will do the trick. Just connect the Zone 2 (or whatever zone you want) preamp outputs from your reciever to the amp and wire the speaker outputs from the amp to the speakers around the house. Done and done!
As for the amp recommendation, you reall can't do better than a
Sonance. Here's a link to their
amps. Find the one that fits your needs and go for it. The amps sound great and are built like tanks. You can stick it on the shelf and forget about it. The cool thing about the amps is that you can send a stereo input which the amp can then combine into a mono output for the speakes.