recommendations for amplifiers that don't emit tons of heat

No mention of price point above.
I have the latest Spread Spectrum Son of Ampzilla MK-2,and I could not be happier It runs in pure class A to 10wpc then class AB .up to 220wpc into 8ohms,
340wpc into 4ohms and throws off very minimal heat. Class leading performance 
And compact in size. $4200 retail.

Roksan Caspian M2.

@audioman58
I’m not 100% on what you mean by braking... assuming it’s analogy for greater control over the speakers, that’s my experience too. The power isn’t so I can rock out and anger the neighbors, but the opposite. In my experience, more powerful amplifiers don’t need the volume as high to get a full, convincing sound.

Is there a point where it gets too powerful, and the sound suffers? I’ve read extremely powerful amplifiers can sound sluggish. Not sure what to make of that.

And budget is $2000. I prefer the bang for the buck of buying used... reputation for reliability is important

Almost any other solid state amp out there will be cooler than the KSA-150 or the VT100. Just saying.

My McCormacks' get pretty darn hot during the blossoming buzz,
 had them cranked for about 2 hours, at must yell to hear guy next to you, as we were in the backyard, and the speakers pointed towards open windows.
 They performed magically, the new capacitors are not even fully broken yet...... as told by Dan Babineau. 
Very happy with these.
The warmup is a bit long, but once zero'd in, its just stunning, its like a laser beam of sound just directly hits you and is perfect !

will never part with them.

600W@8 / 1000W@4
all the power i will ever need.