Best Speaker for classical music

I've heard some Sonus Faber Amati Futura with expensive Accuphase and Luxman gear and they were excellent for orchestral music. The midrange in particular was stupendous in terms of natural timbres and realism.

Hmmm, I would lean to the Rockports, Vienna Acoustics, Magnepan 30, or Joseph Audio.  I have an admitted bias against Wilson and have listened to them many times.  I have only heard one system with Wilsons that I liked.  Similar issues with B&W.  The only advise I can give is to listen to some violin music to determine if you can live with the upper frequencies. 
  

Fully restored Apogee Diva or Full range if your room is big enough.
Its sound stage and imaging is remarkable, very suitable for full orchestration music. 

Classical music is a far more demanding genre

It isn't. It is just as demanding as any other genre though. One recording that can bring most systems to their knees is the Soria series RCA recording of Verdi's Requiem (2nd track first side). But another recording that can do that with ease is the Vertigo white label pressing of Black Sabbath's Paranoid (first cut side one). Taiko drumming on Sheffield is certainly not western classical music either, but you need everything right in the speaker to play it.


Again, what makes a speaker good for one genre makes it good for another. You can't point to anything about classical music that makes it particularly harder to reproduce.