What's better paired with a GTX 1070 for price to performance ect..
Ryzen 7 3700x
Ryzen 7 2700x
Intel i7 8700
Intel i7 8700k
Intel i7 9700k
Ryzen 7 3700x
Ryzen 7 2700x
Intel i7 8700
Intel i7 8700k
Intel i7 9700k
Best price to performance is actually the $200 Ryzen 5 3600 since it performs like a $350 8700k.
The 3700x would be my pick from that list since it is the best for creative workloads by a long shot, but is also very close to Intels 9700k with gaming performance. The 3700x should beat the 2700, 8700 or k easily.
None of those CPUS should limit a 1070, but the 2700x may for high refresh.
What resolution and refresh rate is the monitor? What game(s)? What quality settings? Intel K cpu's will require a more expensive motherboard and cooler or there is not much point in buying them. Now that all of the non k SKU's are out there, buying a K and not overclocking is kinda silly. The 8700 or the 8700k at stock is matched by the 3600. If you overclock the 8700k it will give better frame rates if you are not GPU limited. This would depend on the game, settings, and resolution.
Yes a 3700x and 1070 should be fine for that.
When I say CPU limit I mean a case where your CPU is at 100% limiting your framerate since your graphics card could get a higher framerate with a better CPU. This shouldnt happen with a 3700x and 1070.