Very impressive specs, but totally over the top, that hard drive, way over spec for your needs, think about it, when you need to defrag it will take you 1/2 day to do it, far better with 2 smaller drives in a raid setup.
Motherboard,future proof, forget it, any thing you buy now will be out of date in 6 months, 2 years time you most likely will have to replace the lot, USB externally hard Drive on that size, you need some thing a bit quicker than that.
Replace the E8600 with a E8400 and that will clock to 3.6GHz without any problem.
Sound card replace with a Creative extreme music card, better card, does a lot better job, apart from the fact you only have twin speakers.
DVI cable is too long, unless you intend to have the monitor at the other side of the room.
Best part is your monitor, I've got same one and it's good.
Save some more money and ditch one of the video cards, you don't need it.
How do you intend to connect to the net, because if it's wire less it all depends on your router speed.
One last thing, buy a fridge to put it in, you will need one to keep the thing cool.