> Also, if you are at the point where you need to add a circut for power, you might need to seriously consider cooling, which could potentially be another side quest.

There should be an easy/reliable way to channel "waste heat" from something like this to your hot water system.

Actually, 4 or 5 kW continuous is a lot more than most domestic hot water services need. So in my usual manner of overcomplicating simple ideas, now I want to use the waste heat to run a boiler driving a steam engine, perhaps to directly mechanically run your air conditioning or heat pump compressor.