I'd be a bit weary of the woofer. I've never heard anything about Cambridge loudspeakers. They could be good, they could be awful. Again, not knowing the quality of the woofer I think that's a bit pricey for what you're getting. If you have some woodworking skills, it'd be more cost effective to build your own enclosures.
<b>However</b>, if the woofer is of reasonable quality and you're not very experienced with DIY loudspeakers, I think that's a good way to go. Everything is included, so it's hard to go wrong. A kit like that pretty much guarantees good sound.