Your thoughts on best audiophile speakers in $10,000 neighborhood?

Sonus Faber Sonetto VIIIs are only $7000- you could go up to a Olympica Nova II for 10K. Sonus are "polite" warm speakers and not known for speed or detail. You could go to a Maggie 3.7i for 9K which seems to more closely match your listening preferences if I understand your post correctly (treasure detail transparency not warm) 

Your room is going to be a challenge- anti-rooms off the main room make for cave like echoes. You will need BIG speakers to fill that room.

Your amp is going to be the choke point. Old Nachs are cool but don't have the ability to reproduce the detail you indicate you are seeking.  You will need a tube amp to reveal the details in your vinyl that your speaker is capable of presenting. If you don't need to rock the docks and shake the lakes I'd look for a good used ARC Ref 160S. I have seen them for cheap lately as ARC is about to release the Ref 320M and well heeled ARC fans are trading up. 

Disclaimer:  My first good speakers were Maggie MG-1s which I bought new at Absolute Sound in Birmingham MI in 1977 with paper route money. Harry was an ARC dealer and my first exposure was to the Maggie/ARC matched stuff and I was blown away. 47 years later I still thrill at the ARC/Maggie pairing. I don' t own Maggies right now- I use Bryston Model Ts because like you I have a cavernous room to fill with sound and my set up is not for critical listening.

@mbmi  While my Volti are my choice, they do everything I want in a loudspeaker and more, I too was impressed with the Borresen's i listened to. Both the x3 and x1 monitors were clean, powerful and musical. They threw a wide and deep soundstage. I was also impressed that at the levels they were being driven, there was absolutely no breakup or distortion. Of course the amplifiers feeding them were top notch.  

@aphilc  If you're willing to buy used, then your question becomes what are the best speakers in the $20,000 range.  At 3 - 5 years of light use, speakers are selling at +/- 50% of the original price.  Buy used and make your dollars go further. IMHO

I recommend the Spendor D9.2.  Currently running the D7.2 and loving their sound.  The Spendor D series don't look super impressive at face value but they are the closest thing to a jack of all trades design I have heard and owned.  

Deep special bass impact and tone because of a well tuned long bottom firing flared port. 

An engaging, smooth and detailed midrange that is a trademark of the best British designs. 

Sweet detailed treble that is uncanny at times without being too much.  

Fast, efficient near horn like dynamics. Quick transients with great energy, perfect for following rapid fire rhythm and drum sections.