Looking for ideas - new mono blocks for stereo music

Hello!

I am on a bit of a mission to upgrade my equipment and just recently purchased the Esoteric K-01X SACD player.
In my case, the primary focus for critical listening is stereo music (aka red book CD) from the Esoteric.
My current chain is from the Esoteric through the Marantz 8802A into the Bryston 7B-SST2 powering a pair of JBL 1400 Array speakers.
I am very happy with the JBLs and just upgraded to the K-01X (had the X-03SE before).

Right now I would like to hear some suggestions for new mono blocks. I am already planning on adding the Esoteric C-03X(s) to the system to replace the Marantz as (stereo) pre-amp.

The primary focus is detail and resolution as I really love hearing new aspects of CDs that previous equipment couldn't reveal.
Soundstage and instrument placement are also high on the list. Bass slam / impact is not really a priority since I am stuck in an apartment for the time being.
Another factor is heat - I am looking for an amp, not a space heater. Especially considering the already hot summers in Toronto!
The price ceiling for me is somewhere around $20,000/pair

My current short list consists of:
Grandinote
Pass Labs
Simaudio
Mark Levinson

Now it's time for the brainpool (that's you guys!) to have at it :)

Thanks in advance!