I would not overlook the Bryston SP-1.7 it performs very well for a one-box solution. It is very flexible and contains a totally independent analog preamp. By my standards it was the best Processor for two-channel that I auditioned. I was budget limited to less than about $4000.00 though. So that ruled out some, but most of those, I have at least some experience with, and I dont think the Bryston gives up much if anything with two-channel.
Having said that, I do agree that a stand alone preamp offers the best possibility for two-channel performance. That shouldnt be overlooked as well, if you dont mind two boxes and integration difficulties.