A lot of good information here... BUT... unless you’ve (or they’ve) listened to the same set up with various amps you (they) really can’t conclude much.
I would have no idea what electronics (i.e. source, preamp, amp, etc.) would sound good to you, since I’ve never heard a set up like yours with various electronics - nor, do I know what sounds good to you. That would be true of anyone else posting a suggestion.
However, I can attest to the quality of the sound of Harbeths driven by Hegel electronics - since I have that set up. And... as Alan Shaw suggests... his speakers do, quite litterally, sound best with Hegel electronics. Because I have several Harbeths and I’ve listened to them with various amps - both tube and solid state - I can make this statement - but - only in the context of what sound qualities I prefer.
And... that is the point... you will never be able to adopt all (or any) of the good suggestions in this thread... and... necessarily, achieve the sound you seek... except by mere chance!
So - you should start by contacting the mfr of your speakers and inquire what electronics they use to demo their speakers, as well as seek the experiences of others with your speakers. There is no other way - except - "chance."