My friend uses an ARC Ref. 3 with his Lamm M2.2s, (the more powerful class A/B cousin to the M1.2), and it sounds great. It runs both single ended as well as balanced inputs and outputs, and it has a great remote control that controls everything.
(And, in case you're interested, I use the Ayre K-1xe with my Lamm M2.1s, and it sounds great too, and I recommend it hightly. (But you said you preferred a tube preamp, and the Ayre is solid state.) The Ayre has a remote, but it is only used for volume control and not for switching sources. I know that the Ayre can have its output adjusted merely by changing resisters on the board. Which is something I need to do at some point too, whenever I can stop listening to music, and get my lazy butt off the couch and do it! :-)
My two cents worth.
Good Luck in your search!