Small Room Question

Hi,
I need some help from some of the more experienced folk out there. I am currently driving B&W Nautilus 805s with a SF Power 2 (or occasionally a McCormack .5 Rev A) in a small room (12x14x8). In general I like the sound and don't necessarily need/want deep deep bass (<35 or so), although a little more than the 805s 45hz would be helpful.

My problem is that my headphones sound way better than my speakers with regard to openness, seamless integration of frequencies, lack of boxy sounds, feeling of envelopment.

I want to seriously upgrade my speakers and would like to hear the experiences of anyone who has is similarly restricted/challenged (?) with regard to available listening space. I can place speakers about 3ft from rear wall (covered with heavy curtains). Would floorstanders/electrostatics go berserk in a room this small?

Any help would be greatly appreciated! Haven't decided on price yet but would like the speakers to match the quality of my anciliary equipment so $4 to $6k, maybe cheaper if used.

Thanks
Audioq