Best In Wall Speakers

Hey Folks:

Looking for suggestions for a pair of high quality in-wall speakers that I intend to have integrated into a built in entertainment center in our living room. The floorplan is open-concept and and while the living room area is roughly 20 X 15 it opens into the dining area and kitchen beyond so the volume of space is pretty large. The entertainment center will be built into the corner of the room and I intend to have the two in wall speakers flanking the TV so I need speakers that are fairly narrow but perhaps with a MTM array to allow for sufficient bass energy. I will not be using a subwoofer so the in-walls will be run full range. Some research suggests KEF architectural speakers may be an answer. I've also seen Revel which look decent. I'd like to spend around $2K for the pair but could go higher if necessary. Also, do I need to create a box behind them or will the cavity created by the corner of the room work and should I have the entertainment center built to create the appropriate size cavity for the speakers?