I just made the plunge and got the Factory Outlet QS8's with stands in Boston Cherry to go with my M3's and VP100.

I noticed that the QS8's are 6ohm but the rest of my speakers are 8ohm. I have a Denon 3803 and I only have the option for 4 or 8ohm. So do I change it just for the rear surround? The QS8's won't be in use all the time so I didn't know if this is a good idea or not? Or should I have gotten the QS4's instead since they are 8ohm? Thanks for any help!