HT system budget.
With your budget you should be able to put together a nice HT. You might consider slightly lowering your reciever budget and spending more on speakers as they will make the biggest difference in the audio performance of your system. For example, a denon 3806, 3805, or 2807 would make a great receiver for $1k or less.
With the remaining $2K, consider spending about $1500 on 5.0 speakers in $500 + on a sub. In this price range, I would recommend Axiom Audio, Paradigm, PSB, etc. Check out the 10" and 12" subs from SVS and HSU to finish off the system.
If you want to save a few bucks, Check out the SVS 5.1 speaker/sub system or the Onix X-LS system from AV123.com
I am not familiar with the Cambridge Soundworks system, but it looks like the small center and surrounds would have a hard time keeping up with the mains. Also, I am not sold on the idea of full range mains vs. a seperate subwoofer for HT.