I would say the Ray is better as the Beam has side facing speakers, which need to be able to fire sounds out in the open, so to speak, rather than just to the sides of your cabinet 

They even sell the Ray as being able to be placed on a shelf, in a cabinet like yours.

I would agree.  Although the Beam is 65 cm wide, meaning you have about 20 cm on each side for the side firing speakers...it should be ok.  I just think the placement in the corner isn’t going go be as ideal for sound bouncing off walls,  trueplay tuning, atmos effects, etc, so Ray will work well for your setup.  

Full disclosure though, I have not heard the Ray, and really haven’t heard the Gen 2 Beam either, so I’m going off what Sonos has stated and others on here have experienced.

I’d be tempted to go with the Arc. that looks like a big room.

Arc or Beam you might consider putting the TV on a stand and raising it high enough to clear the speaker. I did that here and am much happier with the sound compared to my Beam sitting on a shelf, a bit smaller than yours.

I have this one and love it. The swivel it provides is great for minimizing window reflections too.

https://www.crutchfield.com/p_051WSTV1/Sanus-WSTV1.html