Advice from Audiogon family - best speaker $3k-$4k

For a nominal investment of no more than $1000, look for a pair of PSB Stratus Gold's (not the i's, however). They will sound like a speaker costing far more. I have a pair purchased by me in 2006 and I will never part with them in the event that I put together a non-reference listening room. I have compared them to the following in my system,

Vienna Acoustics Liszt-No bottom end whatsoever 

Any B&W product-Far too bright and fatiguing

Focal Sopra II-Great mids, but not enough low end

Sonus Faber-Looks good but not exciting from a harmonic perspective

Tekton-Only if the lights were off, as they are not easy on the eyes

Save some money and hunt down a pair!

You may be able to land a pair of Maggie 3.7i used or the 1.7i with a good sub would also be worth auditioning.

Good luck happy listening.

What about used ATC SCM 40s?

ATC are the most accurate speakers, imo. See if you can stretch to the SCM19s ($4700) otherwise the SCM12s

Later add a Dynaudio 18s sub  (~1800)

ATC are a dominating presence in pro recording studios

https://atc.audio

Your B&W are a perfect match for the McIntosh amplification.  However they can be a little stogy in the midrange.  

Another excellent match with Mac amplifiers are the Klipsch Heritage.  

The Forte IV sound excellent paired with your amplifier.  The Forte IV has a lively deep and rich sound and is the more refined than the Heresy.  

Be prepared for a more exciting sound and much more life like midrange,  

Should be able to find new under your budget.