Harbeth M30.1? See here: http://www.theabsolutesound.com/articles/harbeth-monitor-301-loudspeaker/
Your room is not that large, but maybe the Harbeth SHL5+ is also feasible, for a bigger sound and more bass extension. Alternatively, you could combine the M30.1 with dual smallish subwoofers (plus Antimode 8033 room eq), or even the Audiokinesis Swarm system, again with the Antimode (but visually the Swarm might be too overwhelming): http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/
How much power does the power amp provide (good speakers usually like a lot)?
Your room is not that large, but maybe the Harbeth SHL5+ is also feasible, for a bigger sound and more bass extension. Alternatively, you could combine the M30.1 with dual smallish subwoofers (plus Antimode 8033 room eq), or even the Audiokinesis Swarm system, again with the Antimode (but visually the Swarm might be too overwhelming): http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/
How much power does the power amp provide (good speakers usually like a lot)?