I wish I could help you out, but I'm not sufficiently knowledgeable about all the choices.

I will say that I think you should get a bigger subwoofer, if you want to feel things kick. I got the 8D and decided I wanted to try a bigger one almost immediately. On the other hand, if you want to let your son sleep... You might have to turn it off sometimes.

Other threads also suggest the 4Ts are better than the bookshelf speakers for the fronts. They probably look better too.

Still other threads suggest that if movies are your main thing, then you should get a good center speaker.

I watched Iron Man yesterday (Blu-ray) and the amount of sound in that movie from the surround was minimal (I was surprised and disappointed by that). I would say skimp on surrounds and get good front and center. Hunt for Red October (Blu-ray) had more and more interesting surround sound, so I guess it depends on how things are mixed.

Cheers!