It depends whether your priorities are with music or movies.
If you favour music and have another half to visually please, the B&W's will most likely be your preference. But if you're looking to put together a home cinema system, then the M&K's are unbeatable for the prices they're going for at the moment. M&K's are purely designed to faithfully reproduce movie soundtracks whereas other lifestyle packages are designed for music reproduction and aesthetic reasons.
For movie use, the M&K's are so much more open and accurate, and the level of detail compared to the average package is astounding.
As they're an easy 8ohm load, they can pretty much be driven by any AV amp, but we'd recommend at least the Onkyo 605 or something around the £500 mark. What you get from the M&K's will depend what you put in as they are more revealing than the average speaker.