Definitely a solid build future proof build RedDog.
The GTX 1060 isn't weak by any means, but make sure it's the 6gb Version, its a solid 1080p and upto 1440p, 60hz with very high to ultra detail on all games. VR ready etc (if you wanted to go down that route)
A GTX 1070 is for a solid 1440p, 144hz with mostly ultra detail on games. but for the price over the 1060 its not worth it.
I definitely feel the GTX 1060 is more than adequate for that setup.
To put it into perspective though, I'm running an MSI Twin Frozr GTX 770 2gb and this is running some AAA titles on 1080p and some even at 1440p, paired with a i3-7100 and the GTX 1060 is at least 25% better than my GTX 770.
So it's a safe bet and I would say stick with 1060.
An i7-7700k coupled with a 1060 is a beast.
No bottlenecks from that system RedDog, i7-7700k, Z270 Platform, M.2 SSD, GTX 1060 6gb, 16gb DDR4 3000mhz RAM and a solid PSU. Its a great build at a good price.