I’m surprised those B&Ws can’t play loud enough for you in that room. The B&W does have one of the biggest criterias you need for loud volumes and tight slamming bass which is a very inert cabinet. You need a very inert cabinet if you want that hard tactile bass at loud volumes IMO.
my room is roughly 25x18 and both my Focal 836w and my Pioneer S-1ex play louder than I could stand with plenty of bass and I’m currently using subs. Maybe it’s you just don’t like the sound of the B&Ws. I will say at LOUD volumes you can hear the Focal cabinets which takes something away from it. With the Pioneers you never ever hear the cabinet. They have a similar inertness to your B&Ws.
This is with a 100w ss integrated and not even going half way up the volume dial. With my 50 watt tubes it strains but only when ridiculously loud.