I agree with what several others have already said, focus on your speakers first...I've had Polk, B&W, Energy, Monitor Audio, Definitive Technology, Cambridge Audio, Event, BIC, Wharfedale, Sunfire, Pioneer, JBL, Bose, Pinnacle, PSB, and several others. I have sold most of the above brands off, some of which I had more than one model, and have settled on KEF R300s, which someone above has already mentioned to you. The detail and esp the stereo separation will floor you...I also have the R400 sub paired w/them, and am very happy w/this setup. I also have the Halo P5 pre, which someone else mentioned. I bought it mainly because of the built in crossover section...but be advised that the DAC in it stinks. Of course, if you are doing a [mostly] analogue system, that would be a non-issue. I am using a hybrid [Vincent] amp that warms up the sound somewhat ~ overall, a very nice, detailed sound. Oh yeah, I am not doing a turntable at all, I'm using an Oppo UDP 203 to play CDs, which I know is not very trendy right now. How funny that now CDs are "old-school". But some of the things you are looking for [stereo separation, big soundstage] I have in spades. As you know, and many above have already said, it's primarily preferential ~ keep after it, tho, because you can definitely get the sound you want...you just have to keep experimenting.
Well, that was a long and roundabout way of saying, I second the vote for the R300s ;-0