Remember that this machine is being used for general purposes. No gaming. I decided against the quad core because I think the dual core I chose would be faster than the Q6600 I was considering. Any thoughts?
You don't need the heatsink you listed. The E8400 comes with one since it's the retail version. If you do buy a heatsink, buy a S9264 for $10 more. With the rebate it's about the same price.
It doesn't really matter for the GPU, but I would get something fanless. If you aren't gaming your GPU won't produce that much heat and will be dead silent.