For your large room, you probably need to add a sub to get what you are looking for. Even the N802 wont put out enough bass to fill your room. I own the 800D in a room like yours.
The N802s are good speakers. Probably the shining star in the B&W line, both from a sonic and a best-bang for the buck catagory. IMHO anyway.
Myself, I prefer the Revel Studios, (I bought them a few years ago), which if you can wait for a good deal, should show up used for around $6K.
You did not say what you're using for an amp (other than it is a Krell), but the Revel's need to have a fair bit of power. 150 wpc is the minimum I recommend. 100 wpc works, but just to a satisfactory level. 200 wpc will really bring the Revels to life. IMHO of course.
(My Revel Studios fill my 16'x24'x8' room more than adequately. Too much for my wife, but then again, she is not into listening at realistic sound levels. They have really good bass, tight, quick and clean.)
Good Luck in your search.
The Watt/Puppy 5.1, Revel Studio & N802 are among my top 3 picks. Should the Krell Resoultion 2 be considered in this mix? Are they sonically comparable to the above? The downside to the W/P 5.1 is that they're getting a bit old by now. I could get the Revel & N802 @ a couple of years old.
My Amplifier is rated @ 200 wpc.
Size of the room is a problem for really filling with bass, agree with Nick. However, IRT the N802 and D803, there is no comparison. Buy the D803. It is better in every way then the older N802. Buy a new pair if you have to and have the dealer hook you up with a sub. If you like the B&W sound of course.