Z,welcome. Yes, the 5 HDMI input requirement does limit the choices. The two new Denon models that you link would be fine and the similarly priced Onkyo models would drive the M80s just as well, since their amplifier sections are quite powerful and have tested well at 4 ohms. I'd mention the 876 in particular, which is available for a little under $1000 now from Shop Onkyo. 4 HDMI inputs, however, and the new model isn't in yet.

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Enjoy the music, not the equipment.