SINCE you didn't put in a price, I'll tell you that the "greatest system in the world, at any price" (Quoted from Stereophile Guide to Home Theater). This system won the 2001 Stereophile system of the year.
5 ATC Active 100's plus 2 of the 01/15 1000 Watt Subs will run you around $58,000. For your sized room, you'll need a much more dynamic speaker. Go check them out in Stereophile GTHT and check out their new website at www.atc.gb.net!
Each Active 100 is internally Tri-Amped with 50Watt Tweeter, 100Watt Mid, and 200Watt Bass. Active Crossovers always make for a better speaker sound than internal Passive crossovers w/ external amps.
I guarantee you that this system will blow the living doors off of anything else in the market place... I have never before seen people coming out of the CEDIA demo room that actually broke a sweat before. Nothing short of awesome.
Lower budget lines are available from ATC which are just as astounding as almost all of their products use the same drivers w/ different sized cabinets.
Lastly, this is the system that I own....