Audio Note AN-J vs AN-K

I know this is not what you are asking but let me throw in my 2 cents. My listening room is exactly the same size as yours. I have tried floor-standers and stand-mounts galore. The bigger speakers "load" my room way to prominently in the bass region to the point where the sound gets tubby. I am certain many tweaks to the room could be made but I chose not to go down that road. The best speakers for my application were smaller stand-mounts which render a natural presentation. So, just be careful. That's all I'm saying. You may want to try 3/5 iterations in that room and see how you like them. That works well for me, even for rock and orchestral.