I have two suggestions, based on recent auditions and a purchase:
Instead of stand-mounts (and sorry, they're a couple hundred bucks more but don't need stands), but the
Focal 714V impressed the hell out of me in all the things you're looking for--clarity, midrange purity, air, detail, room-filling sound and ambience, nice tight bass. They're very petite--about 36" tall x 8"w x 11.5" deep. These speakers immediately disappear when the music starts. Normally $1200/pair but marked way down for MusicDirect's moving sale at $719 with free shipping and return privileges.
Second, after auditioning a bunch of stuff, I came home with some Magneplanar 1.7s. Too big and too much for your stated needs, but you can get the MMGs factory-dierct for $599. They're so thin and light you can tuck them up against the wall and then bring them out just to play the music. Maggies are magic. No boxy resonances or noise floor. Music and a well-defined soundstage just floats out into space. You don't listen *to* Maggies so much as listen *through* them.
Still, for maximum transparency and room-filling sound for minimum floor space, those 714Vs are hard to beat.