The sony speakers seem great, what do i specially like is their response bandwidth, 50-50k, all the PC speakers i have found have a response banawidth of 50-20k, does it make any difference?
The only problems with these us that they have got a push connector? how can i connect them to my pc?
The human ear can hear 20Hz-20kHz, and that's the best case scenario (in most cases, it's more like 20-15k). So, the 50k capability of the Sony speakers is completely irrelevant, unless you like annoying your dog (which can hear up to around 35k). Also, unless I'm reading the specs wrong, all you get with the Sony speakers is the speakers - there is no amp included (so you would need a separate amplifier or receiver, which would add quite a bit more money). I'd say that the Creatives are definitely the better choice here.
Sony requires Amplifier/Receiver which sounds better than the Creative at higher volume. The Creative will give you a better sound when the volume is low and at higher volume it'd be likely get more distorted.
As cjl mentioned Sony speakers still require an Amp.
Bigger is better up to a point where quality is in question.