Oh and for box speakers one of my current favourite lines is Von Schweikerts, not mentioned so far. The one in your price range is VR-4SR Mk II, 12k I think. A short blurb from their page to show what level of speaker we are talking about here:
"Studios using VR-series include Sheffield Labs, Musical Fidelity Sound Labs, A&M Records (Herb Alpert), and Walt Disney Studios (Alan Menken, winner of 7 academy awards). Many recording engineers brought these speakers home, including Robert Harley, now editor of TAS, and Herb Alpert, creating an audiophile demand."
http://www.vonschweikert.com/zvr4sr.htm
These really, really do something special - and in my opinion come closer to the planar sound than most box speakers (part of why I like them).
But I still slightly prefer the Magnepan 20.1s or Sound Labs.
One thing I didn't ask - both 20.1s and Sound Labs require large living rooms. If you don't have a certain size living room, then the VS would be a great bet. Oh - and while I might get flamed for this (bring it on!), if living room size is a factor, see if going to the Magnepan 3.6 makes a difference, while no 20.1 I think it will hold its own or beat many of the suggestions you have in this thread at half or less of their cost.