Also, Why the E6600?
Depending on Budget, Chips such as the E6320 or E6420 which will be released around April 22nd may be a much bigger bargain.
When designing a system, step one is to decide on a budget that you want to work in and then to build around that. For most systems, the GPU is more important than the CPU so we need to make sure to not constrain your system by over spending for the CPU.
Also, the E6600 will drop significantly in price shortly.