About the difference between reciever vs. seperates.

It really depends on what your personal needs are. A top rated pre and power amp, like the 950/7100 combo, will almost always have a more dynamic sound and power reserve than even some of the best receivers. If you have extremely efficient speakers and your budget is a higher priority than overall atmosphere and sound, go for the receiver. If your speakers are less efficient and you want to have a more "theatre like sound presence" seperates are the only way to go.