$3500 floor standing speakers used. What would be your choice ?

everhard, appreciate your suggestion. I have not heard Andra but read about them. How they would work with my amp is something that I can't really know.

Yeah, I'll keep my current speakers in any case for as long as they can be kept operational. So far, as I upgrade amps and cables they sound better and better. In fact, they are very sensitive to even very minor changes, and I like this. the entire system is very tunable.

Fyne speakers are 8 ohms and efficient so should work great with your amp. They are designed by engineers who left Tannoy. Their SP models are very nice. 

Check out a pair of Usher DMD Diamond Two Floor Standing speakers, They are a very fine speaker 2.5 way, they are around 50" tall, have a curved back, biwired, with cast iron bases/stands and very nice wooden veneer sides in various finishes and play all types of music.

Aerial Acoustics, 10T - not easy to find, big & heavy but for $3-$3500 used, Mike Kelly's masterpiece is still an amazing system. 
https://www.stereophile.com/content/aerial-acoustics-10t-loudspeaker-page-3

Here's maybe a fly in the ointment - https://ohmspeaker.com/

I have a pair of Ohm Walsh Tall 3000s in my factory loft living room listening area. My now favorite speaker, they being omni directional. Great that I only need to get them about a foot away from the brick wall, 11' ceilings, 17' X 30' factory loft setting. And the sweet spot is very wide, tall.  Started years ago with Thiel CS series, then to ELACS, KEFs - all good. But Ohm Walsh series really shines.  And in your budget range for sure you can get a pair of Walsh Talls that fit your listening room. If I knew how to post a .jpeg of my setup I would. Oh, almost exclusively PS Audio high-high end pieces. Even heard PSA's Paul McGowan, on a couple of his daily podcasts, compliment the Ohm engineering having know Ohm's original creator/engineer (just recently RIP).