if you dont play the latest pc games or do heavy video editing any computer you buy will be more than sufficient for your needs. if you want a better looking case then you should build. as far as the processor intel and AMD make great processors. the only reason to pick 1 over the other would be for cost savings for building yourself or brand loyalty really. but if i had to pick one of the links you posted i would go with the first link you posted. that is similar to the one i just built from newegg over a month ago except i got a different processor (amd fx 8350).
