Shopping for a new receiver but I'm a bit confused on something. I'd be looking at future state as a 5.1.2 setup, or 7.1.2 at most. My question being what should I be looking for in a 7 channel receiver, that will allow me the ability to add an amp for a 9 channel setup down the road? Also, is it way more cost effective to just spend the extra couple hundred dollars for a 9 channel receiver? I know the alternative would be an extra amp for 2 channels, but I have never shopped for a stand alone amp before. Thanks!