???Compromise???

I'm not sure what you define as "front end" but yeah, I've given up a lot of cables, and a lot of size, in favor of good room acoustics, less complexity, more visual beauty and aesthetically pleasing components.

Front end is turntable and phono stage- or CDP if you're not into the whole must sound like music thing. 

If you're talking about amps the heat output is trivial, a few hundred watts, no more than a few light bulbs. That said, I had a class A integrated for a while which being solid state they never sound good unless on all the time and so the heat from something like that would be a turn off.  

But in general, let me get this straight. Whole room, well over a hundred square feet, devoted to audio. We're worried about the few square inches difference between amps? Really? And heat- your body puts out something like a hundred watts just sitting there. One person. Figure another hundred watts per light bulb. Plus who knows how many thousands when the sun is out. We're really worried about the tiny little difference between amps? 

Front End:Amp/PreAmp or Integrated amp..
SOURCE:DAC/CD Player/Multi Disc player,DAP,Turntable etc...
Speakers:self explanatory...

I have small stand mount speakers and a single box network receiver in my apartment.  I have lost jaw dropping sound in exchange for very good sound and a wife who isn’t complaining.

I accept the fact that one may need to invite two burly friends over to help to move to speakers, but I resist components for which you need an engine hoist cherry picker to maneuver into place.