I'm trying to help a friend build his system; however I don't know much about home theater. I'm a 2 channel guy. His system : B&W CM9s with center channel and subwoofer, ATI 3003 amp, currently using a Yamaha receiver's preamp out two control his system.I'm looking for recommendations for a preamp/processor below 2K.
What change is he looking for?

He's looking to improve everything: detail, bass, just a cleaner/more open sound.
Sorry for the error. It should read: to control his system.
I have a Cary Cinema 11a he can have for $1K. It can provide the sound and control he's looking for, but speaker setup requires a tape measure and sound level meter, and, as seems common among higher end processors, it does not do acoustic room correction, although it has a substantial equalization menu.

Marantz AV8801 is now $1500 ($2100 off original price). I bought one to replace my Marantz AV7005.
I firmly second the suggestion of the AV8801.
GOOGLE the reviews

All digital HDMI with no legacy inputs or outputs...a good thing going forward.

Convinced me enough to sell my top-eend CAMBRIDGE AVR and go for separates with this unit as the preamp/processor ffor AV 7.1 purposes