Reasonably sensitive speakers for tube amps, max $2k/pair, new or used


While this topic has been covered before, I'm interested in both recent experiences with new products or anyone who just would like to chime in.

I have a couple friends interested in tube amps, lower wattage -- 40 wpc or below. Before they pull the trigger there, they need to find the best higher sensitivity speakers they can, hopefully at $2k or below, new or used.

QUESTION: What high sensitivity speakers would you recommend to them, new or used? What did you try and NOT like?
Characterizations of their sound, experience with a trial period, the company, etc. appreciated.

I'll pass the best answers and links along to them.
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@zazouswing Room's about 22 feet x 14 feet x 8 feet. Omegas are an interesting idea. There's an Omega 7xrs set used for $800 on audiomart I was eyeing for my friends. Hmmm.
If you are stilling looking, try Monitor Audio Silver 300's great pairing with tubes. 
They might not be easy to find but a pair of Spatial Audio speakers would fit the bill nicely.  I recently upgraded my very inefficient magnepan MMGs to a pair of Spatial Audio M3 sapphires and am absolutely blown away at them.  I’ve read nothing but good things about all Spatial Audio speakers — I tried to buy a used pair of M4 turbos but someone beat me to it — that was about six months ago on the used market and the price was $2000 on the nose. 
Yep I have a pair of Spatial M3 Triode Masters-- 5 watts to 400watts--it just works well.