Best high-efficiency speaker under 10K

I have never played in the high-eff speaker / low-powered amp space, but I've read so many things that I would like to give it a try. I own an EAR 859 integrated amplifier, De Paravicini's interpretation of SET. It's pretty incredible, especially if you consider its price tag. I am now in the business of choosing the right speaker. I listen to a lot of jazz and vocals and opera. So, I can do without the sub-40HZ frequency range. I would like to stay between $3K to $7K, certainly below $10K. Here are the options i am considering:

1) Zu Audio Essence.
2) Beauhorn Virtuoso (single driver)
3) KCS louspeakers (the model that uses the SEAS exotic driver)
4) Devore Gibbons 8
5) Living voice Avatar

If I had to choose right now, I'd go with the Beauhorn, but I know their limitations.

Any thoughts/personal experiences with the above or any other speakers in this range? Thanks.