£15k $22k to spend on speakers...but which?

Charles, the speaker/room interface is so critical and when you have limited placement options, you never know. As much as I love Harbeth, I could not for the life of me make the Monitor 30s work in my room. They just hit the wrong nodes (I guess) and they sounded like the bass was absent below 100 hz. I probably could have made them work with a pair of Mapleshade Bedrocks, but I didn't feel like going that route. Good bass, but reduced image height, as I recall. My friend who bought the Pharoahs has very good ears and I believe him when he said they didn't work for him. That's why I insisted on a home audition before plunking down 12.5K.

I have a nice pair of Verity Sarastro MkII for 16k they would sound great for all your tastes in music.

I would likely move up to the Olympica 3 from Sonus so as they are not as bass deficient as the other speakers listed. That being said, the Sonus Faber's have a distinctly different sound signature in comparison to other speakers you listed. All the other speakers mentioned present a more forward sound that gives great immediacy and very present sound. The Sonus are more a bit further back but still provide an excellent level of performance that draws the listener in.

I would suggest to listen the SF's first only to determine if that is the sound your looking for. If you find it too non involving, then its clear the other three speakers would likely suit you better. I might add in the Kef Reference 5 or Blade 2 in your listening sessions as they are a bit even handed on the treble as compared to the Focal, but without any loss in resolution or soundstaging. But listen to the SF's first just to get a feel for their style of sound.

With that front end I'd suggest used Rockport Altria/Avior, Magico S3 or 5 (but Q3 should one appear at the right price easily bests them), or Focal Utopia Scala.
Can't really go wrong with any unless you've a tiny room?
All are a significant step up from Olympica/Sopra level. For what it's worth adding subs is a whole level of complexity and room thing compared to simply getting your speakers right and with any of the above quite unnecessary.

In januari the new Monitor Audio Platinum series will come
out. The Pl-500 is one I would put on my list if I were
you.

The price in Europe will be 20.000 euro. I think it will
be between 20.000 en 22000 dollar in the U.S.

It is a 1.8m tall speaker what has 3 separate parts. It
will not be a wide and deep speaker. It weighs 120 kilo.
It is a 3-way D'apolito system with 4x 20cm low freq, 2
midd drivers and the new 100khz ribbon tweeter. This one
is wider and bigger than the one who is used at this
moment. It will create an even wider and deeper stage.

I am sure it will be the marktleader in a 3 dimensional
holographic stage. They use a new way of connecting the
low freq. drivers more from the middle. This creates a
superior timing. The ceramic with aluminum drivers will be
the benchmark in response and timing as well.

The front side is with new high quality leather. It is a
lot more smooth compared to the Platinum at this moment.

Internal wiring will be 100% silver and they use the best
and most expensive WBT speaker terminals.