I go to cambridge soundworks for everything. I love their speakers. Real value for the money. Only other option I would do is Best Buy, but I would have to do som much research, etc. Camb. SW has a limited number of components and their own brand of speaks and I have learned to trust them and have been rewarded with a great sounding stereo for a decent price.
I just have the ensemble II which is only $200 now. Not a powered sub but sounds great. I would suggest you go to their site at
http://www.cambridgesoundworks.com and type in "ensemble" and look at those choices as a starting point. THere might be a store or reseller near you - you can look up locations on their site.