i would suggest the z97-k motherboard, its the cheapest of the z97 series but still a very good board and capable of "k" cpu. i use this myself with a i7-4790 and a gtx 980 and its superb.
and actually i don't totally agree with outlander_04 on the psu question. i would get at least a 600W psu. i'm not saying he's wrong, because the system will run fine with 450-500W psu, but if you are looking forward to overclock cpu and gpu you will need the more wattage and its always more safe to be over the requirements with a bit.
Yes with a GTX 970 4gb, and i5-4690k you will be very happy, because you can run any 2014-2015 and upcoming games even on ultra settings with 60fps on 1080p .