I think you're better off getting separates. A dedicated amp is going to produce more power and the sound quality should be better. I've had some nice AVRs, my last one being the Onkyo TX-NR3007. Processors change and you may end up upgrading every 2-4 years while a good amp is something you can hang onto for a long time.
I've owned some of the amps you're considering (or similar models). Some that have been through my home theater system include a Rotel RMB-1095, Sunfire Cinema Grand, Krell Showcase, and Lexicon LX-7. The Rotel was nice, but a little "dry" and "grainy". The Sunfire was a step up in refinement and dynamics, but a little "rolled off". The LX-7 is still in my system, however I now have some Rogue Audio M-180s powering my mains. The LX-7 handles my surrounds.
I recently purchased a Marantz AV7704 to replace my AV8801. While this might be considered a "downgrade" going from their top of the line to the mid, I'm quite happy with the AV7704. I use a separate pre-amp for 2 channel listening, but if I did not, I think the 7704 sounds as good as the 8801 and doubt I could have been able to tell them apart in a blind listening test.
For your budget, you should be able to put together a decent system. I think I paid about $1400 for the AV7704 (refurbished) and the Lexicon was $1300 used when I bought it. The LX7 is a little long in the tooth now and you might want something newer (although mine still works great). I have not heard them, but have heard very good things about the Cinenova amps. A used one would be on my short list if I was trying to do what you're doing today.
