Minecraft No Lag Computer Help

Hello everyone as you probably already know minecraft needs a powerful CPU and RAM so i might buy a computer with but but can you guys tell me if these are good builds:

http://www.amazon.co.uk/gp/product/B005FCN62W/ref=noref?ie=UTF8&psc=1&s=computers

OR

http://www.amazon.co.uk/VIBOX-Storm-Computer-Bulldozer-Processor/dp/B007PBHC3A/ref=sr_1_1?s=computers&ie=UTF8&qid=1336294354&sr=1-1

Because i heard a couple reviews about VIBOX's blowing up and stuff so which one would you guys go for? I personnaly love the vibox case but really don't want it to break within a week.