300, local pick up or over the internet? Or? Either one will get your foot in. you're only thinking of adding Atmos. Adding what funds you do have, add those funds for a Newer AVR!
According to your post you must have something already driving what speakers you do have. What is it you don't like about what you have already. Nothing in your post of any gear you have already. Or are you asking which one to validate spending the $300 on? You already know what you want, right? Or else you wouldn't have come up with those two options you must have done some research. So pick one! Breaker breaker. Whats your 10-4! Mr. BigRigBob,10-4!
Any Smokies spotted! Eastbound & down short time to get there!
Enjoy.
Don't you already have a Denon AVR? What is it your looking for in the other two you listed. You also have satellite speakers.
Stay put with what you have now. You are about to waste a lot of money on minimum improvement if any.
I found out that info from your other two post, you get 3 guess and 1 doesn't count.
Cheers!!!