I'm looking to buy a new AVR. I have a 5.1 speaker set-up GM Epic 350. Can you run a 7.1 system with 5.1 in the hopes of maybe adding 2 more speakers later? Not getting two more speakers soon, but want to buy current AVR. Any comments? I'm looking at the Denon 2105.

M22ti,vp150,QS8,EP350