HELP Why no bass? Why bright?

You made no mention of your room or what you like to listen to by the way. See if you can find a Stereophile test CD and check your system's bass response. If the B&Ws are performing sorta close to spec then you really do not have a SYSTEM problem. Speakers are usually responsible for the bass performance. The amp can not create it if the speaker will not support the lower fundamentals. Alternatively borrow some Krell or Bryston amp/preamp combos and see what your system does then. Make sure everything is wired properly too.

Thank you all very much for your responses.

Ok, looking at your current equipment and needs I'd recommend the Wharfedale Pacific Evo 300. It's Bi-wireable so you can bi-amp, has a soft dome tweeter so no harsh brightness, and has tight defined bass. It's also a damn good looking speaker IMHO, and it's kevlar drivers and real wood veneer will resemble the B&W. You will give up some of the speed and details of the B&W, but I think the Wharfedale's smooth presentation will win you over. Check them out at IAGamerica.com

one last thing, if you do move to the wharfedale keep your DH labs silver cables, a bright cable will be a good fit with a laid back speaker like these.

Before you toss the B&W try hooking them up to a Classe CAP 101 or 151 integrated. I heard this very setup and there was plenty of bass but can't remember if it was too bright. Didn't seem that way to me at the time.
Read some reviews on Classe int. and I think you'll find they are voiced somewhat "dark" and with plenty of bass.