HI JServ,
I have M80's powered by a separate amp. My receiver is an Outlaw 1050 which is conservatively rated at 65 watts. I switched to an Aragon 4004 that I picked up used on Audiogon for $600 (2 x 200w). It powers the M80's while the Outlaw drives the 3 other channels. The improvement in performance was very dramatic, at all listening levels. A lot of people say you will notice a difference only if you crank up the volume, but I found improvement even at relatively low levels.
I set the M80's to large, and I'm running a sub.
There is a difference in volume levels between the mains and all the other channels (center, surrounds). But this is easily adjusted into balance using the receiver. I'm sure your HK allows you to adjust the channel levels independently as well, so this shouldn't be a concern.
I think the Rotel 1070 will work well for what you are trying to do. Check Audiogon or other places for used equipment and save a bundle.
