What preamp for Lamm M1.2 ?

I, too, chose the Lamm L2. What a combo.

FYI: I upgraded from my Ayre K-1XE, with its optional phono boards, to the VTL TL-6.5 line stage preamp with the Basis ASR Exclusive phono preamp. These work even better with my hybrid Lamm amps, (M2.1 monoblocks),than my Ayre did.

My friend's ARC REF. 5 preamp works really well with his Lamm M2.2 monoblock amps too.

Yes, I've heard the VTL preamps and the ARC preamps create good synergy with the Lamm Hybrids. They are great choices.

I've had the Lamm M1.2's with Wilson Maxx 3. The ARC ref 3 and 5 sounded SHRILL! Stay away. I strongly recommend the Aesthetix Callisto Eclipse. Pricey but fantastic.

I clearly liked the Mac C500T better than than the Ref 3. The C 2300 sounded almost as good.
The luxman c800f was better than either Mac. The Aesthetix is perfect.

The ARC/Lamm combo will always be influenced by cabling, the room, and
associated equip. Not sure what those other contributing factors are, but
they play a major role in the sound. Having said that, there are a number of
Lamm hybrid users that I have successfully married ARC Preamps with
Lamm amps. Tricon_dave, here on AGon, is one such person. He was
using an ARC Ref 5SE with Lamm M1.2s. Perhaps you should reach out to
him for actual ARC/Lamm experience. So even though we each have
varying opinions, in the final analysis, your ears should become the final
authority.