What an amazing system you have. I can almost hear it. Obviously this has taken an incredible amount of time and effort to assemble.
I’m an old guy as well. I stayed away from tubed amplifiers for forty years for the same reasons you state. Wow, what an incredible mistake that has been for me. When Audio Research offered an Auto biasing and soft start amp I instantly took the plunge. From that moment forward there was no going back.
As you age I think experience allows you to appreciate the more nuanced and subtle aspects of life... and of course music. While I was really excited by a powerful kick drum or loud guitar solo as a young adult, I now get the subtitles of great performances and venues. After attending the symphony for over ten years in the seventh row center seats... the Audio Research amp changed my system from a sound spectacular to sounding like real music. Completely changed the character to sound natural and musical. There is a known synergy between Sonus Faber speakers... which I have and Audio Research.
Given your budget you owe your self a trial. Find yourself a ARC dealer and have them bring over a set of Reference 160m mono blocks. They should set them up and leave them at your house for a week or two. This is what my dealer did. I left my old Pass x300 sitting next to it so I could swap in and out to decide which I wanted. Within a minute I realized there would be no swapping... they would stay. The reputation of tube amps has outlasted its useful life. With auto biasing and soft start these are very reliable amps... know I have put well over 5,000 hours of time without any hiccups. If you are getting absent minded, as I find myself... don't worry after two hours without a signal, the amp turns itself off.
Life is too short to compromise.