V, welcome. The power needed would depend to a large extent on how loudly you'd play them, but if you use a comfortably loud level that won't cause hearing damage any of the receivers rated in the 100 watt area will do the job. This applies to both the M60s and the M80s, since actually the M80s are a bit more sensitive and therefore require a little less power than the M60s. My suggestion to fit your budget would be the factory refurb(if anything, even more likely than a brand-new unit to be trouble-free)Onkyo 707 from
Accessories4less for about $450.
