I really like the $1,000 Denon X3300 on sale for $600 on Amazon.
I've used the X3000s with my previous B&W 802D2 and Phil3, and my current RBH SV831/1212 towers.
There may be more powerful amps available, but in terms of Preamp/Processor, I have full confidence in the Denon X3000 series w/ Audyssey XT32. Just make sure you put a 120 mm PC fan atop the X3000 AVRs.