What preamp for Lamm M1.2 ?

I have listened to the two of them at lemgth. If I had not heard the L2, I would have thought that the LL2 was their best line stage. To my ears, the L2 is just a bit more refined in the highs, more neutral and extended in the deep bass (the LL2 has just a slight bloat in the bass that makes it a little "warmer" sounding and in some cases perhaps more pleasant-sounding, particularly if you don't have true full-range speakers), and overall perhaps a little better at layering in a soundstage, i.e., a little better at presenting low-level detail spatial cues. While the L2 is solid state in its signal path, it sounds tonally like a tubed preamp, so I would not be deterred by that aspect.