J, you used the term "strained", but that's usually more characteristic of a speaker becoming distorted because of having to play too loud in too large of a room. If that should be the case, then getting an amplifier which has enough maximum power output to allow clean amplification at a maximum level 3-4dB higher isn't going to help things if the speakers are already what's "strained". Be that as it may, if you get one of the units that you list, you can be assured that they're all well-designed and won't add any sonic coloration to the sound of the M3s.
