XR500 SYSTEM NEEDS GREATER RANGE

Thanks for the read in advance.
my equipment:
xr500, sx10 switcher, s8000 switcher, and a ex7000
2 users, 5 lg smart tv, 2 cell phones, 4 MacBook’s, iMac, gaming/vr console, WIFI smart switches/plugs, Sonos 2 systems, echo dots, 3 x 6 each Arlo units. oh, and a Ring door bell.
Ethernet cabling is cat 6, and brand new. All terminating to the device, not a wall outlet, straight runs. Using rg45 t-568b straight.
The home is a 115 foot long frame ranch style with a concrete slab basement. 3500 sqft and 2500sqft. all wood frame. The attic runs the length of the home and is 8 feet tall at the highest triangular height..
My goal is to produce the widest/strongest dual band signal for all devices, wired and wifi capable.
At my disposal is the Orbi RBK50, EX800 or the Orbi RBK23 [only because the box said 6000 sq ft].

How would you set it up. What and where. Thanks