Is it possible to build a quality home theatre speaker system using different brand speakers? The reason I ask is that I own the Denon AVR2805 and 2 pairs of Acoustic Research tower speakers and that is is it. I want to add a center,rear surrounds and sub and I hear that you should stay with the same brand(voice matching). I am looking to spend around $750 for speaker system that needs to be small but very powerful becauce I have the 2805 and a very large great room 23x18. Any help is appreciated.