Well I believe the R7 is a better speaker than B&W’s 703. The 800 series I think might be bette than the kef but you’d have listen for yourself. Personally I would look at Revel first and then kef or Canton.
Should also find out your budget. That’s a big space and you’ll want to spend some good money on subwoofers. Rythmik, HSU, SVS, PSA, monolith all make excellent performing subs and will be better than “speaker” builders such as kef or revel, klipsch etc.
Lastly, whoever at BB said that .2 Atmos is better than .4 should be fired, or at least have their HT sales privileges revoked and made to sell vacuum cleaner bags. Or HDD’s, or maybe urinal pucks. Yeah, that last one.
That’s ridiculous. Can I ask what logic that person gave you? I’d honestly love to hear.
I’m with your local shop on this one.
So, what’s the budget?