Bookshelf speaker with electrostatic sound

Hi,

I'm looking for recommendations for an efficient bookshelf speaker for my second system in living/dining area. About 3,000 cu. ft. Vaulted ceiling goes to 14". They will sit on top of 12" deep bookshelves, about 6' high. They'll be used primarily as background music at low to moderate levels.

I've had various electrostatic/tube systems for 30 years. I like the open, quick boxless sound from electrostatics. So naturally that is my reference. I realize I can't replicate that sound in this application, but I thought it may help with recommendations.

Tonal accuracy and balance is important, especially at low to moderate levels. No rolled-off or excessively bright treble, or overemphasized bass or treble for affect. Rear porting or emphasis on porting for bass will probably not work. I'd like to avoid speakers that exhibit nasal qualities. Not interested in speakers that demand really good amplification. I deal with that in my other system.

Initially they'll be paired with Onkyo TX-8555 receiver, but I'll consider a small integrated down the road, tube or SS. Just want to keep it simple for casual listening. Source is radio and digital. Prioritized music tastes are classical, jazz, folk, blues, rock, alternative.

Budget: Less than $1,000.

Thanks!

Scott