Hello Ano
I have an Antique Sound Labs MG S1 15 DT integrated tube amp, 5 watts per channel in triode and 15 wpc in pentode. I only use the triode mode because it is so much sweeter sounding. I've used this amp with Axiom M3Tis and at 5 wpc the amp had absolutely no problem driving the M3's. I currently use a pair of Michaura M66s which use the same 6.5" (2 each) drivers as the Axioms and the same 0.75" tweeter used in the Meraks. The sound stage is huge, imaging is breathtaking, and the music is sweet. I wouldn't worry about whether your amp can drive a pair of M60s since these speakers are even more efficient than M3Tis.

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.