Speakers for large open room

Even before I saw that you have b&w's, I was going to suggest B&W Matrix 801 SIII's. That's if you have the room for such gigantic heavy speakers, & if you want to go to a more powerful amp(s). Theil 3.6's are another suggestion. Also B&W Matrix 802 SIII's, but you'll need more power for either of those as well.....

I had the Matrix 802's in a smaller room, with 240 wpc. Gorgeous on Orchestral music. Merlin VSM's would be nice if you want speakers that don't need a lot of power, but I'm not sure how they'd work in that size room.

For that kind of money you could get stacked Altec Model 19's. :o) Those should fill the room nicely.

Avantgarde! Duo or if budget allows Trio

Big Tannoys from the Prestige range.

Yagbo12...I'd have to give up my new flats boat for the Avantgardes! Would anyone consider Vandersteens for this room?