GTX 970 4 GB
MSI Z170A
I5 6500 3.2 ghz
8 GB corsair ram
I’m looking at at least high graphics with 60 fps(1920x1200). Is this a realistic expectation?
No, your video card won’t let you to have such FPS. It won’t be able to render all the frames, that you processor will draw. 
Will overclocking my GPU put me close that goal? Or is my GPU still not cutting it?
It’s not. Not on high settings. 
Your PC is capable of running medium settings, possibly 60FPS. If you want ultra/high, you need at least 16GB RAM, CPU is just good for high settings.
So if I were to get 16 GB of ram, and overclock my GPU, do you think that would be enough?
overclocking won’t save this situation
Lower your graphics details, that’s solution.