What is your BUDGET? Will you consider a horn speaker? I have a room larger than the one you speak of. After a long search, I ended up buying Viking Acoustic Grande Voix dual horn speakers. They absolutely fill the room with musical bliss. Check out the Viking website.
Speakers for a Large Room (20’x37’)
Open concept listening space with speakers on one short wall and kitchen at the other end. Furniture about fifteen feet from speakers. I assume I'll need large speakers and am considering Klipsch Cornwalls as well as Tannoy Ardens, but open to suggestions. I also assume standmounts are too small for the space. I should mention I mostly listen at low to moderate sound levels, occasionally cranking it if the wife is out. Thanks for any input.