yeah, I was in the same spot as you were 2 monhts ago...
the problem is that G-sync™ raises the price of monitor considerably compared to Free-sync™.
Thank god that now with new Nvidia drivers (and DP cable) some monitors are actually (unofficially) supported for G-sync even though that they support only Free-sync.
So i bought me a DELL S2719DGF for about 350€ and couldn't be happier.
Pretty much all of the above that Aeacus has listed are double the price of that Dell.
I can only highly recommend it, only downside is TN panel, other than that I'm very happy with it.