You sound like a candidate for horns or some type of pro speakers as it seems high sensitivity and efficiency seems to be your main concern. That said most won't have the fidelity of the Axiom system. I would suggest buying as much power as you can afford. Maybe even look into some pro amps. The M80's are really geared for very high power handling. The limit will be the amp feeding it.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne