I bought everything in there is in my cpu online except the HDD's and the power supply and the case :D you just have to look before you buy
you get your stuff from amazon tiger direct or if you have a US billing crdt card then newegg also you can get from sidewindercomputers or frozencpu or performance-pcs

there are many good websites :) the ones i mentioned are ones i personally tried or know they are good

you can try from ebay also but you will not have a warranty for that product most of the companies dont accept the warranty if you buy from ebay :P dunno why

and no use of the warranty also sending back the defected product is like 285 for the first lb then 85 for the each next