Hi
You will no doubt get a lot of suggestions so I will add what I can
I have owned and used Sonus Faber speakers for about twenty years now currently I run Guarneri Homage the originals. My amp recommendations would be
David Berning ZH-270 ( My previous amplifier) A true classic and this amplifier was used by SF to voice the Stradavari I believe.
LSA Statement ( This is the amp I currently use )
Line Magnetic 519A could be worth a listen as could the Mactone which is used by a very knowledgeable and experienced audio friend who also runs Sonus Faber speakers.
Yes the Gryphon and Dartzeel amps are wonderful but I am not sure you need to spend that much money as if you do your speakers will likely become the weakest link.
Good luck