How to wire a speaker to multiple amps/preamps?

I am considering having in-wall speakers installed by a professional (including wiring and separate volume controls), but I'd like to keep the front-end electronics up to me so I can take advantage of various deals here and other places.

There will be two "source" rooms, one with a stereo music setup and one with a home theater setup, then several other rooms that have pairs of in-wall speakers controllable using either setup as a source. Each room with in-wall speakers will have independent impedence-matched volume controls.

Wiring the various electronics together is no problem for me, but is it reasonable to do the front end wiring of the speakers to amp or receiver myself? How does one hook up a set of speakers to two different amps?