Integrated amp suggestions.

Audition one of these with a Super Black Box.  I don't know much about the company but auditioned a unit at the RMAF and if I had the budget I would be considering one.

https://www.stereophile.com/content/octave-audio-v-80-se-integrated-amplifier

If you want to stay with the McIntosh house sound, you can pick up their best integrated (300wpc) for under 10K. 

Simaudio or Luxman 

If you can get a great deal and like the sound why no go for it.
Pass would be another brand to consider put if you can't compare go with the sound you like.

dan d was krell’s main man before his current outfit bearing his name

i have not heard his current super duper expensive stuff at any length but if it still has the same sonic signature as krell then it would be classic clean sharp bass slammy solid state... can be lean and sizzly if matched poorly to source and transducer

ayre’s house sound is somewhat different, a little warmer, sweeter, a little less bass slam a little more air and subtlety

also suggest hegel and belles - excellent sounding units, very good spatial capabilities