I figured in the size of that room that you'd probably want to go with four surrounds and four Atmos speakers. So, that's an eleven channel setup, or 7.x.4. The middle "x" is subwoofers, and ideally you probably want two of them. Your receiver is capable of a non-Atmos 7.1 or a 5.1.2 Atmos...
You'll probably have to upgrade your receiver, or go separates, to get the 7.x.4 setup you're probably heading toward.
I noticed from the photo that the receiver has zero ventilation. I mean, there is a shelf about 1/16" above it. That will positively destroy the receiver. It needs room, and a...