Bob, you may want to contact some local audio shops which carry tube amps. They may have a used one and could demo it for you. If you go used, you should make sure the transformers are in good shape - absence of hum.
Although some disagree, in my opinion, a good tube amp, especially a Single End Triode type, just sound beautiful with the right speakers. The M3s are an easy load for a low power tube amp. I do not know why the M22s should present a more difficult load (their sensitivity rating is about the same) but they just do, or at least the pair I had did.
Tubes not only sound great, they also glow in the dark.
Some tube amps which I've heard and like very much:
Jolida, Antique Sound Labs, Prima Luna, Cary, Hafler, some older ones: Dynaco, The Fisher, H. H. Scott, Harman Kardon.
Good luck!!
