Recommended Speakers with Krell 450Mcx Mono Amps?

My system consists of a pair of Krell 450 Mcx mono amps, Krell HTS 7.1 pre-pro, Totem Wind loudspeakers, MIT Oracle 3 cableing, Revel B15a sub and Esoteric DV50s CD player. The room is a large 20'x20' family room with 2 story ceiling and not a lot of walls for reinforcement and modest acoustic treatment. My music preference is jazz, accoustic, classical and vocals.

I've tried several different speakers in this room and can't seem to reach audio nirvana (B&W matrix, Totem Forest, Piega P10 > best of them). It seems my bedroom system presurizes the room nicely and has great imaging (BR System: Totem Forest, Marsh A400s, Audio Refinement pre, Krell Showcase DVD), but the main system is lacking something.

The main listening room does double duty with home theater, but my 2-channel is very important to me. Preference will be toward a more compact footprint and the ablity to place the speaker near the front wall (12"). I'm flexible with the price, but would like to stay under $12K (or so) on the used market.

I'm open to any and all suggestions. Thank you.