I would second the choice of Merlin VSM-Millennium with the Atma-Sphere. See a recent post on audioasylum.com of someone who uses VSM-M with the M60. Better yet, get Paul Speltz's Zero autoformers and run the M60 with half of the tubes. See link on Zero, as well as numerous posts on it on the Atma-sphere Owners Group site:
http://www.condor-connection.org/asog/tweaks/ps/zero/index.html
http://www.condor-connection.org/asog/bbs/index.html
Good Luck
http://www.condor-connection.org/asog/tweaks/ps/zero/index.html
http://www.condor-connection.org/asog/bbs/index.html
Good Luck