The only issue with matching an amp to speakers is the amount of power the speakers need (see manual), and how much distortion you are willing to put up with (at any price range).
B&W is a superior line of 'box' speakers. They deserve a distortion free amp: Hafler DH-200,220; Rotel, and Anthem lines have great specs too, for all they show (no IMD given); Muse 160; and ATI, for instance. Bry$ton and Jeff Rowland De$sign Group for those who just want to pay more :-)
Notice these amps range in price from $200 to over $8k. The ATI is probably the best value (build quality/superior specs/price). The specs are about the same throughout (except as noted), which is about as good as it gets.
If you get close to the speaker mfgrs. max recommended range, you put the speakers at risk. Better to stay under and have the amp clip first where you have the chance to correct a problem before damage is caused. Going a little over the minumum range may offer a 'sense of ease' at higher volume levels.
Those interested in 'true to the original' for the sonic charcteristics for their system tend to cross over to dipole speaker designs. Becasue of their directional radiaion pattern, as opposed to the 360 degree pattern, and inherent cabinet resonance distortion problems, of the 'box' speaker designs.
The dipole designs go far too in solving those pesky room resonance anomolies that smear the sonics throughout the frequency range by tending not to excite the pressure modes in the first place.
The open baffle dipole designs tend to also solve the low frequency integration issues with planer and ELS designs, and offer a much wider off axis 'sweet spot' listening position (you don't need a 'head vice' as with ELS, planer models :-)
They are both good speakers - a matter of taste, so I would hear them with your favorite CD, or better yet bring both home for a few days, and go with the one you like - make sure no re-stocking fee.