Red Dragon Audio, Still in business?

I don’t have experience with their 3+ channel amps but from what I’ve gathered they are not quite as well regarded as the 2-channel models. 

Last I knew, they had shut down a long while ago. But their website does show a 2024 copyright.

Have you ever lived with a high “power” class D amplifier? I ask because 500 WpC of Class D will tend to perform more like 100 WpC of class AB in practice. They tend to struggle with dynamic loads (which speakers are of course) in my experience. 
 

I would take a 300 WpC class AB Parasound amp over any class D amp of any power rating. 
 

Since you like Parasound amps and want to save some coin, I highly recommend seeking out an original Halo A21 amplifier, preferably one of the later production units so it’s no more than a few years old (a serial number in the six thousand range).

The A21 actually measures better (lower noise and distortion) than the newer 21+ despite the spec sheet claims. The difference is audible too. I actually prefer my late production A21 to the $6800 Coda No.8 V1 that I owned previously. The primary distortion of the A21 is second harmonic which is very uncommon for solid state. 

The A21 mated to a highly transparent preamp such as the Benchmark LA4 or Topping A90D makes for great synergy.