I have the Sonus Faber Elipsa SE Red speakers, baby strads:) I use an Audio Research Ref 110 to power them. When I upgrade, it will probably be to the Audio Research Ref 150 SE. I definitely would want more power than the Ref 75. The Ref 110 is about perfect.
If I were going to move to solidstate, it would probably be to something like the Pass Labs XA150. The Pass Labs amps are a great match with Sonus Faber speakers. Though I will say that I a pair of Simaudio 400M monoblocks in my system some time ago. These were just excellent sounding amps and they did not get hot.
Keep in mind though that while everything is important. The preamp is going to have more impact on the sound then the amp.