I agree with the above poster. The CM9's are very nice speakers but like most B&W's, have some pretty low impedence dips. Therefore, they will perform at their best when given plenty of high current power. The kind of power that very few AVR's can provide. Unfortunately that means your Yamaha RX1020 too - its power supply is simply too small to deliver the current that the B&W's will demand. There are those who will say your AVR will drive them. Sure, it will but you'll never hear the peak performance the CM9's are capable of and why pay 3K for a pair of speakers and not hear everything they are capable of.
I would be looking a high quality power amp for the CM9's too. I think the one you are asking about is the Marantz MM8077 because the AV8801 you mention is a pre/pro. While a huge step up from your Yamaha 1020, this power amp would not be high on my list for the CM9's. It has no rating into 4 Ohms and the CM9's will dip below this number from time to time. Also I found the following article interesting in the reveiwer actually thought his Anthem PVA7 has more balls than the Marantz. And the Anthem is rated at fewer watts per channel too. Its all about current delivery.
http://www.hometheater.com/content/marantz-av8801-surround-processor-amp-mm8077-amplifier
Don't get me wrong. I like Marantz, especially their Reference gear. I am just not impressed with what I am reading about this model. There a lot of other power amps at the same price as the Marantz you can choose from - Odyssey, Emotiva, Parasound, Anthem, NAD, Rotel, etc and I believe all of these list their specs into 4 ohms. These would be amplifiers you can trust to properly handle the CM9's. Good luck!
