From what I have been researching, the HK's would be good enough to drive the M80's with out any problems. I have had my eye on used ones on Ebay, 1/2 price for both the exact same models you listed. As far as the Denon goes I own the 1804 and I would recommend you look at the 3806 or 2807 as these are the latest from Denon. The 2807 is a little cheaper and almost identical to the 3806, HDMI 1.1 compatible but has a few watts/channel less. I am struggling right now to not get anything but I am leaning towards the 2807(new) and the HK635(used) about the same price and virtually the same features ie. auto setups etc.


Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70