As dakkon mentioned, I did switch over to using four Halo A-21 amps to handle the five M80s. Each two channel amp had 400watts @ 4ohm, the 80s had no problem handling the power from the Halo units, and as several forum members can agree with, I could run the system at very high volumes.
The reason I went with seperate amps was simply due to the amout of air I have to fill with sound, in my enviroment, I leaned that the multi channel amps would simply not handle the five M80s, the multi channel amps would simply go into heat protection mode after about 15 to 20 minutes at SPL levles above 105db, and it was usually the amps in the center of the unit that would give up first.
I'm not trying to convince you to go with seperates, or change your decision on which units to purchase. It all depends on the size of your listening area, the volume level you desire, and how much you care to invest. I know there are several memembers running four 80s on multi channel amps and have no problems, as well as some using seperates.
Just giving you my expierances, and as usual, its just my opinion, in my listening area, so take it for what you think its worth.
Good luck on the hunt and decision making, which ever way you go, the 80s will handle the power, and be very happy with all you can afford to give them.
