I'm planning to use the zone 2 output on my Onkyo 805 to power speakers in different rooms of my house. In order to do this I need a speaker selector like the following.

http://www.amazon.com/PSS6-Six-Zone-Ster...56823753&sr=1-7

http://outlet.crutchfield.com/p_190SS4/Niles-SS-4.html?cc=07&search=speaker+selector&ssi=0

http://www.amazon.com/s/ref=nb_ss?url=se...elector&x=0&y=0

http://www.crutchfield.com/app/product/s...elector&x=0&y=0

Are all of these selectors just setup so that the speakers are wired in parallel? So if you have two 8 ohm speakers then you have a 4 ohm load on your amp. If you have three of them then you dip below 4 ohms and I may have problems, right? Are there any speaker selectors that have a way around this low impedance problem? What is the most that I would want to pay for one of these since they can range from $30 to $400 or $500? All I want is a selector setup for four rooms and I don't need independent volume control for each room. Obviously I want my Onkyo 805 to be able to drive this at reasonable volumes as well.

- Nick