coldmachine, if I understand correctly you have 4 outdoor speakers (all NEAR A8s?). Are you using the zp80 or 100? If 100, are you using the wiring in parallel like they show on the sonos forum? I have enough 100s to use one of those, but could also see using an old AVR (I've got a Denon 2803 lying around gathering dust) that I could use with an 80. I did order a pair of the A8s; plan to hook them up and see if I feel 2 speakers is enough.
Dedicated to keeping my 2 labs from chewing any of MY stuff.