Aside from the usual non answers there appears to be some consensus that you may want to start a serious assault on the summit of a well integrated synergistic system by looking at changing your speakers. It is an old axiom that the speaker accounts for the vast majority of the sound quality and flavor of any system. Therefore start by building around your speakers.
Personally I found that the amp I use has a very, very important role as well. I finally switched to tube power amps with some unusually good trannies and my system came alive. People kept asking how I had modded my speaker after that amp change.
