I gotta say - I would recommend that you go with a straightforward HTIB (Home Theater In A Box) setup like the Onkyo S770
Onkyo HTS770S for $399.99 at PCMall.com
http://www.pcmall.com/pcmall/shop/detail~dpno~507415.asp
Then you hook your sound card up (digitally) to the receiver, you have 6.1 channels of decent audio with real speakers and decent amplification.
The DVD player I won't comment on and the TV should be good. You may want to check to see if your PC supports 1080i or 720p output, and see if the TV supports that as an input and you could hook your PC up directly to the TV for video. Then you really wouldn't need a DVD player at all, but could use your DVD drive inside your PC.
The amp you have listed currently is a TWO CHANNEL stereo amp and won't play with the speakers you have listed which are specifically designed to connect to a PC and are really just small cruddy speakers that will not give you nearly the sound that you may be hoping for. Read the SPECIFICATIONS - not the hype. It says 2500 Watts on the main page, then the actual specs show 4 watts per speaker (!!!) and 18 watts for the sub.
The Onkyo, in contrast offers 6 channels rated at 130 watts, but more likely an honest 70 watts RMS per channel plus a 220 watt (probably pretty close) subwoofer. They list the speaker range as 30-20,000hz which is likely a LOT more accurate than the 16-20,000hz that Sony claims. 16hz from a PC package sub??? whatever
Not sure what your actual budget is or the availability of Onkyo if you are not in the USA, but I imagine you can get it with similar pricing.