Theta Dreadnut or 3-Plinius 8200P

Purchased used Silverline Sonata MKii. Need great amp for two channel and HT. Probably will purchase Classe ssp30 or equivalent processor. Dreadnut or Plinius?
My suggestion is both sound very good. However, one other option, if your looking into a 3 channel amp, is to look seriously into the 3 channel Pass X150 X 3!!! If you are lookng for a 3 channel amp, you will not find a better sounding one for those speakers!
Anyway, it' a thought.
I'm not sure if your only looking for those brands, but I'd thought I'd suggest other options.
Good luck
I use a Dreadnaught with a Theta Casa-Nova pre. No complaints here. I fear a Classe pre may color the signal a bit (warm). I've owned two Classe pre-amps in the past. I would recommend taking a good hard listen to the Theta Casa-Nova they are going for very cheep right now in the used market.

Sorry never owned a Plinius.
Any comments on the classe CAV-180
I owned a CAV-150 and a Classe 301. Used them both in my H/T system for a good six months. After purchasing the Dreadnaught I dumped them both and never looked back. IT'S THAT GOOD!