The one thing you really want to listen for from an in-ceiling intended for home theater is how well it presents sound into the room/into the main listening position. With the common design being stationary woofer and pivoting tweeter, high frequency clarity is permitted to carry into the room, but mid-range, mid-bass, and whatever usable bass is confined to about a 3-4' downward radius. The main negative with this, in my opinion, is that the center speaker suffers from an overall lack of presence and sounds far removed from the images on-screen.
With this, it would be a good idea to check out the Speakercraft AIM 8 or AIM 7 series speakers or the Sonance Ellipse product. These are two lines that you mentioned above engineered to be in-ceiling home theater speakers since they allow the full range of sound, and not just the tweeter, to be directed into the listening room . For your budget, the Sonance will max it out - retail pricing for your front three (Ellipse 1.0) is 1k. With Speakercraft, you can probably get into (5) AIM 8 One's with a small dealer discount, but I would opt for an upper level pair of either AIM 8 or Aim 7 models, a matching single for the center, and if budget is close to gone, using a pair from the AIM 5 line for the surrounds.
Obviously, there are so many more speaker options out there, and you have also mentioned Klipsch and B&W, but the Sonance and Speakercraft are models I am most familiar with so can only offer advice on them.
Hope this helps and good luck in your search.
"What's better? A great 2D movie or the worst 3D movie?" - Stephen Colbert