surround processor?

I have a 5.1 channel MC-12 I no longer use. I’ve been meaning to post and sell it. I loved it for surround sound, nothing close to it, very flexible, an amazing pre-amp for that use. Matches well with any high quality amp. 2-channel was good, but still no where near the quality of a dedicated 2-channel. Just depends on what’s most important to you.

Imho, 'surround' can work....but it has to be approached with the care that MC has towards 2chan....but, again, mho

2 speaker and home theater are entirely different. You listen differently. HT is a visual experience with potentially a great immersive sound. I don’t listen to my Marantz 11.2 system for the accuracy of the gun shot sound. I do listen to my 2 speaker pass labs system for the accuracy of the piano. HT subs should literally shake you. 2 speaker setups should have subs that extend and melt into the sounds of your front speakers. My surround sound speakers don’t begin to match the quality of my 2 speakers. And they don’t have to. Having a creepy sound behind you doesn’t have to come out of $20k speakers. I love both setups. But HT and 2 speaker are mostly different systems because we listen differently to each setup. To answer your question, I bought the Marantz many years ago because of the 13 channels and the auro 3D. It’s modestly priced and works well. 

Make sure what you get will do at least 4K video, the Classe mentioned above does not.

Make sure what you get will do at least 4K video

Absolutely. Clarity of sound and clarity of image are the way to go. Substandard surround speakers are like a substandard center speaker; not recommended for those who appreciate quality.