Opinions On Used Speakers music only $5K $6K

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.

My first thought is a pair Avalon Radian (maybe HC or if you are lucky a pair of Ascent).

I'd suggest the Daedalus DA-1's. They will love the high current delivered by your Krell and make beautiful music. Check out my review posted here on the A'gon as well as comments by many devoted fans. Do a search under Daedalus.

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.

Dunlavy Vs will fill your room. Properly placed, they actually disappear.

Who is the kind soul that lets you audition so many different brands and purchase from the internet?

:)

Access the auditions and PERHAPS consider Merlins,many paths to salvation I'm told,good luck,Bob

A used pair of Wilson Watt Puppy 3-2 at about $4000, or 5.1 at about $5500 are great speakers that will be better than the B&W N802.

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.

There's a pair of mint Dunlavy SC-IVa's listed: http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1147120084

Also, have you looked at Theil 2.4's or larger?

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.
Nick