The reason I suggested the Harbeth M40.2 and not my personal favourites the Quad electrostats is that by the description this is for a very large room where the Quads would struggle.
For a review of the M40.2:
http://www.theabsolutesound.com/articles/harbeth-monitor-402-loudspeaker/A lot of amplifier power would be a good idea in this case. Alan Shaw, Harbeth’s designer, recently demonstrated the M40.1 in the Netherlands and the power meters on the demo amp indicated more than 500 watt per channel. Fortunately watts do not have to cost much if you use pro audio amps rather than fancy overpriced high end hifi. A good example would be the Yamaha pxx00 series. See here for a test of the 2x350 watt rms P3500s that until recently sold for about $500 and performed better than some boutique amps costing ten times as much:
http://www.homecinema-fr.com/forum/amplificateurs-de-puissance-haute-fidelite/mesures-ampli-yamaha-p... I bought the 2x250 watt P2500s for my son and the sound quality is perfect. Alan Shaw has long argued that Harbeth speakers will perform perfectly with any properly designed amplifier. He has also argued repeatedly that you do not need fancy expensive cables. If you think you need them, your system has a problem.