A list of efficient speakers at ~$5K a pair.

The Fritz Carbon 7s is hard to beat with your requirements. A step up would be the Joseph Audio Pulsar Graphene but at a cost. Please take a look at these other options with benign load requirements, in that price range:

https://nsmt-loudspeakers.com/Performance-Series

https://shinjitsuaudio.com/

https://www.pispeakers.com/contents.html

Dieter