alazanto,
If this is your first purchase of a "serious" integrated amp, then I would avoid tubes altogether. Due to their low damping factors (high output impedances), most tube amps are far from neutral when driving real-world loudspeakers; the frequency response will partly follow the speaker's impedance curve, especially in the bass region. I believe that what people call "tube sound" comes, in part, from this, as well as from the non-linear components such as output transformers, plus the relatively shallow negative feedback used in most tube amps (because of their low open-loop gains). These also constitute what I had called the "fun factor" -- depending on your taste and amp/speaker/room matching, a tube amp
could produce subjectively better sound than modern solidstate amps that tend to be completely flat and accurate in objective measurements. In other words, the technical inaccuracy exhibited by tube amps are, in general, subjectively quite benign, as many tube fans will attest.
That said, if I were you, I would still start with a plain-flat-and-accurate, good solidstate amp first. After all, you want to have a solid "reference" system first, right? Especially given that the virtue of the M22ti is its superb accuracy, I would first mate the speaker with a highly neutral, colorless amp.
Among the candidates you listed, I do not personally appreciate the fact that the Marantz has the
minimun recommended speaker impedance of 8 ohms; although it will be fine with the M22's, I have to say that the amp might be less versatile than the British brands you listed. But you may or may not mind about this; other than that, the Marantz certainly has the highest rated power, which will never hurt.
Cheers!
