What to get depends mostly on your monitor resolution.
For a single 1080p monitor with 60 refresh rate the 6GB GTX 1060 should do fine for anything higher the GTX 1070 will be a better choice.
If you can afford it, the 1070 will give you the best performance. Averaging between 15-30 FPS more than the 1060. Either one will be fine, pairing with an i5-6500.
What to get depends mostly on your monitor resolution.
For a single 1080p monitor with 60 refresh rate the 6GB GTX 1060 should do fine for anything higher the GTX 1070 will be a better choice.