Thanks all for the thoughts thus far. I didn't get to play it but I did see a CASA head in a guitar store in Paris. That thing was huge for a solid state amp, so it's striaght off the short list.
I went up to Bass Direct last week, and although I walked out with a new guitar (oops) I was really hoping they would have the MB heads, but they had neither the LM3 or the LMT 😢 that I could try.