Are you 10 boxing? Why the two video cards, just to use more monitors instead of doing a PiP?

I'd throw in a cheaper, small SSD if you're going with this type of system. Otherwise the hard drive will be your bottleneck.

Is there any reason for the expensive NIC?

That's a huge PS, but maybe you need it for the dual video cards.

Do your research on the case and make sure it's a good choice from a cooling standpoint. I'm very happy with my AZZA and with the amount of fans it's keeping things nice and cool (without the need for the water cooling on the CPU).

I think the upgrade to 1600MHZ RAM is very inexpensive, especially in comparison to your other choices.