YOu can have the most expensive speakers in the world but if your amp cant drive them properly it will sound like shit. Always match what you have. If you buy a thousand dollar amp then your speakers dont have to be all that. You putt a crappy amp to B&w's you will be ripped off.
If your gonna buy b&w's plan on spending 4k for a good amp. Your processor alone is 6k made by lexicon-Mc-1 Plan on spending big bucks just for bass. let the subs to the pounding so your channeled speakers dont work to hard. Good luck building a systemn is alot of fun and takes thousands of dollars and time. I spent 12k just on subs and cooper cables.
Just placing your subs is a project in itself let alone tesing acoustical feedback for placement of speakers and setting milli seconds. It's a sickness for me when it comes to this I love it. ICQ me if you need help here are some links.. You have to tewll yourself what you can afford then go by that. Under 2k just go to best buy.
lexicon.com-processors
sunfire.com-subs/amps
Klipsh kicks ass for the money and is perfect for Home theatre.
Grab two of these

Grab 4 of these

Grab 4 of these
You will have full range audio. Get a good center and 2 side channel hanging klipsh and your rocking.
My system is 9 channels
front right
front left
center
right rear
left rear
right center
left center
Subs which are amplified already.
couch channel for installing vibrating modules in your couch.
Good Luck SNOW