I want to order an XPA2 but it is 300watts per channel. I am probably going to up grade my M60's in the future, will this be a problem running on the M60's on this amp now?

Nope.

Greg, it isn't entirely clear what "problem" you might foresee, but if it's that the Axiom spec for the M60 is "only" 250 watts, this is inconsequential. First, maximum power specs are typically conservative and the speaker can handle significantly more(although your hearing can't)without going up in smoke. Next, you(not the amplifier)control how much power the speaker actually uses by your choice of loudness level. Regardless of whether the amplifier has a maximum capacity of 30 watts, 300 watts or 3000 watts, the M60 uses about 1 watt at a comfortably loud average listening level. Brief peaks take much more, of course, but rarely more than about 100 watts at safe listening levels.

Thanks for the info guys. That is what I thought just wanted to be sure.

Headroom Headroom