Not sure what fast's priorities are with a speaker, but the Vandersteens are an excellent suggestion. In your price range, I would also look into a pair of German Physiks (the entry level floorstander is ~$16-18K). Personally, of all the speakers I have heard (many, but certainly not all) in this price range, those are what I would buy. They have everything that I seek: A huge 3-D soundstage, smooth yet detailed treble, wonderful tangiability and timbre, finely gradiated dynamics, an "in the room with you" presentation, good bass (but I would add subs), and they completely dissappear into the soundstage.
If you are serious about the KEFs, I recommend two things: First make sure you like the tweeter's presentation. Some people, lilke me, find the KEF treble a bit too "in your face". Second, push the dealer for a professional setup. IME, KEFs really need good setup to realize their full potential, moreso than many other brands.