Why are you getting an add-on ethernet adapter when the motherboard has one? Get a WD Blue or Black instead of the Seagate Barracuda, more reliable.
As pointed out above, single 980 is a better idea than dual 970s and you don't need that much RAM, at least before you use the system for a while and see how it runs. Two 8 gig sticks is plenty, even 8 gig is enough for most use.
I'd also get a Blu Ray player/writer instead of a DVD one to give you a bit of flexibility with movie playing.