I'm currently saving up for a Pioneer Elite VSX-74TXVi 140 x 7 to upgrade from an Onkyo TX-SR503 75 x 7. It's just 8ohm and that's it. I was wondering which floor-speaker sounds better the M60 or M80. And if the M80 are indeed the better speaker could you point me in the direction of a good 2-channel amp to power them where my receiver isn't 4ohm capable?