5 wpc were plenty for my M3s, 3.5 watts is in the flea power range. If you're ready to drop a grand, why not pick up an ASL MG S1 15DT or PrimaLuna integrated amp? The former will give you 5 watts of SET gold, and the PrimaLuna is rated at 30 wpc, I think. Although the first watt is the most important (if the first watt isn't good, who cares how many more like it are lined up behind it?) you want a bit of headroom, don'cha?

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