Editing (video & photo) / Gaming (mostly dota2) monitor

[MrUnsure4123]

Here is the spec of my system.

GPU - GTX 1070
CPU - i7-6700k 8M Skylake Quad-Core 4.0 GHz
RAM - 16GB (upgrading when I feel like to)
500GB SSD + 1TB HDD

I'm just a average person that likes to edit random videos (1-2x/month, short videos) and plays game (mostly Dota2) when I have time. I'm looking for a 1440p monitor (either 27" or ultrawide).

Questions:

Do I really need a G-sync monitor since I have NVIDIA GPU or it won't really make a difference since I don't edit or game as much, just only on my free time.

Should I just stay In 1080p for cheaper option?

 

[cwli1_]

The higher the resolution the higher the cost.