Your next step being the M60s is a good one. They will probably be louder than your mits front stage is right now as they have pretty good sensitivity. Keep in mind that there won't be an abundance of bass though. This is true with all speakers at those wattage levels though.
I bought the M60s about a year ago and hooked them up to an Onkyo tx-sr501 (65x5). They sounded great. Much better than my bose 401s. Then I upgraded to a Pioneer Pioneer VSX1014TXK (120x7). Hooked it up 5.1 initially, sounded even better. Then I biamped the M60s with the extra 2 channels. Sounds phenomenal.
I think the point I'm trying to get to is that you'll be really impressed with the M60s right away, and they will continue to amaze you as you upgrade.
Adam
