980 vs 970 builds Need help making CPU choices

Solution
If your just gaming ONLY, then the i5 + GTX 980 is the best choice. But if you do lots of multitasking, game recording, or any other CPU heavy stuff, then the i7 is a better option.
Is your Build a M-ATX Must? Some like a Small Compact PC with decent aesthetics.
The i7 4790k, With a Good Overclock It can beat out any other Processor in some games. Including the recent Haswell E SKUs.
Depending on the Game and Engine an i5 can get very similar results with a GTX 980 . Tomb Raider is a good example of a GPU bound Title . While Far Cry 3 and Far Cry 4 will have different results across the board with Intel and AMD CPUs. the i5 2500k clocked High enough can beat them all out. If Price is not a big deal and you think you may overclock Then an i7 4790k has my vote. Though an i5 4690k would do just as well in games. Right now 4 Cores is more then enough for Most PC titles.