No such monitor exists.
This is the cheapest G-Sync monitor I can find.
Monitor: AOC - AG241QG 23.8" 2560x1440 165 Hz Monitor (£399.95 @ Amazon UK)
Since the Jan. 15th GeForce driver update, Nvidia Control Panel now allows users to "Try" adaptive sync in AMD FreeSync monitors with their Nvidia GeForce GTX 10 and RTX 20 series GPUs. Nvidia claims it may work, it may work poorly, or it may not work at all. But I'm just letting you know you can "Try" an AMD FreeSync monitor with your Nvidia GTX 1070 and hope it works.
I have yet to try my AOC - G2460PF with my Nvidia GPU. Hopefully I can get around to doing that soon so other will know if it works.