I haven't totally decided. In the long run I just want the best bang for my buck. My wife will monitor the $$, so I don't have an unlimited budget, but she is flexible if I do research and make a sound purchase (e.g., $2100 for 1.8 MKII's in cherry and mint condition). I was told that an amp would open up my Danes and let me really hear them, but I don't play music or HT that loudly. I know that NAD's receivers are made to handle 4 ohm loads, so I could always do that, but I must admit it is appealing to go for separates. Having said that, I don't think that I will spend over 2K on an amp (probably not even that much, just depends on the deals I see) and not more than 2.5K on an amp and a pre/AV receiver if necessary. I think it is probably best if I go with an amp that will push 5 channels, though I don't know if it is an absolute necessity since my rears currently are Bose 201's and likely will never be more than some Dynaudio 42's.
Still pondering what to do and will gather as much information as possible before making my final decision.