Tube Mono-Block Recommendation

Currently I have the Bob Carver 305, Looking to upgrade to something else in the Class A Region. Budget is around 12000 US, New or Used any recommendation.

I like the Amps, to be fast, Accurate and musical as possible. Giving me close to Transistor Amp Clarity but with the magic off tubes.
OK--Iv made up my mind. Im going for the Atma MA2 Monsters. Seems to be the that's fits my requirements.
I must say after emailing VAC, BAT and a few other companies to me Ralph provides best customer service. Responds super fast. This is another reason why I have gone down the atma route. Im not into super coloured Midrange or slow sounding amplifiers. I hope this is the last Amplifiers I buy.
Still leaves me wandering How the Atma will compare to the David Berning Quads Z Amps. The QuadZOTL seem to run cooler with less Energy consumption, heat and less tubes. Since im from a tropical climate. Still need to consider these as a option. I like the classical looks of the Atma but heat and power as my current deciding factor. Will probably need to research more.
I had an Atma-Sphere MA2 in my home a few years back and will say it is one of my all time favorite amps ever!

Yes they run hot like ever other Class A amp but boy do they sound good!

You know how you look back on gear you wish you would have purchased or keep. Well this is one of them.
Sounds like you made a good choice. I like that in the summertime I can pull out half the tubes in my Atma-Sphere amps and still get great music at lower listening levels! We're in the second week of a heat wave here and it really makes a difference!