The 480 definitely over the 470
The CPU is a bit trickier.
The extra cores of the i7 won't do you much good unless you stream your matches as well.
However, the 4790k has stronger individual core performance, which does help (although it really should push you from "well enough" to "way more than enough").
Is there a reason you're not comparing it to the i5-6600k or an i5-7600k even?
But I'd definitely go for the i5+480 combi