which preamp with the Lamm ml2's?

I wish your advice to purchase a preamp that matcheing really good with the marvelous ml2's Lamm.
I give very much importance to the musicality associated with a good soundstage ad plenty of detail.
Lamm L2 Reference
My dollars went to buying a new Wavestream Kinetics pre-amp from the Analog Room in San Jose, Ca. IMHO this is the best pre-amp or in top 5 at least. However there are excellent used Lamm pre-amps for sale on Audiogon at a good price. Beyond Lamm it becomes a personal value/performance choice from a wealth of excellent new or used pre-amps. Search the threads for best pre-amps.
Gerrym5,which is the output impendance of wavestream and about his retail price?