Clay, welcome. You shouldn't need to bridge your NADs to have plenty of power for the M80s, which are slightly above average in sensitivity and are by no means "power hungry", to use the term that's sometimes used without any thought behind it.
Incidentally, on bridging, although the language about the amplifier "seeing" an impedance cut is half is seen fairly often, it's technically incorrect. The windings in the speaker drivers establish the impedance of speakers and can't of course be changed by the amplifier. What's actually happening is that when bridged the amplifier is theoretically delivering twice the voltage into the speaker. Due to to Ohm's Law(I=E/R), current(I)is proportional to voltage(E)and when the voltage is doubled the current is also doubled, as it would also be if the impedance(R)was cut in half.
