Speaker recommendations 10 to 30k and no beryllium

You can get a new pair of YG Acoustics Vantage for at the top of your budget. Perfect fit for your room.

Spatial Audio X2 is a well reviewed (Absolute Sound recently)dipole speaker and uses an AMT Tweeter for about $9k. I have their M3 triode masters and they’re great sounding speaker and well engineered to reduce room interaction and produce a coherent sound image. Plus they look cool. 

Sanders Sound. Makes one product. Midpoint of your budget.
Nothing comes close. Read up on Roger Sanders.

@gadios.  

+1

 speakers and amps are some of the best in the industry!!!!

 Roger Sanders sound systems.  He is one of the inventors of the panel speakers.  
Or the one to make them worthy!
his Magtech amplifier are the ones to actually drive those MBL Radiostrahler monsters.

Try one of EgglestonWorks speakers - New or used.  I have the Rosa. Bought it used.  Amazing for a room about the same size as yours.