What I focused on during the research was to pick gears that can produce wide sound stage, great 3d imaging, airy voices, and great details with smooth yet realistic sounds.
To me, what you’re looking for is right in line with what McCormack amps do very well. If you go on Hifi Shark and search McCormack you’ll find several nice used units. The issue is that the older models made in the mid/late 90s are starting to have their input boards fail, which basically requires a rebuild of the amp. I had this issue with my DNA 0.5 Rev A, but I’m not sure if the DNA 1 has the same issue. There’s a DNA1 deluxe for $999 and a DNA 1 Rev A for $1500 (probably the best $500 you’ll ever spend in audio if you can stretch a bit as this is a really special amp for the price). You can call Steve McCormack at SMcAudio and he’ll let you know if an amp may have the input board issue. Or you can wait until a DNA 125 comes available, which was a newer model and shouldn’t have the input board issue. In any event, I think sound wise a McCormack amp would be a superb fit in your system. Best of luck.