Congratulations! You are clearly on the path to a great audio system. Speakers are really important… they must speak to you…they must evoke an emotional reaction. Given your room… you definitely need to push the upper end of your budget… like used Sonus Faber Olympica 3… or better… if they speak to you, like they do to me. I am on my third set… given the size of your room Sonus Faber Amati Traditional would be appropriate… but those are $30K. Take your time… if you have to get more inexpensive ones to prove the the connect, that can work… then in a few years upgrade to the next level. Over the last ten years I owned Sonus Faber Cremona, Olympica 3, and now Amati Traditional… each step has been incredible. My room is about the size of yours.
Make sure the AC is removed and quieted… big time. Otherwise it will really screw up your noice floor.