you could go i7 and not i5, you've got a z board so you can OC, the more expensive Z boards may have other features, more usb3, 3.1 etc.
however I would save it in case you need new win10. If you don't then perhaps an m2 drive if the board can take it, if you didn't have the 960 already then i'd go 970, i5 + 970 is a very good balance with little compromise.