Your advice about a gaming monitor

Hi, everyone. I am planning to purchase a gaming monitor for my brand new gaming rig.
I prechose 2 Dell monitors:

The first one is expensive, with G-Sync, 165 Hz and vertical mode (tate mode).
The second one is much cheaper and curved (I love that) but with 144 Hz and no tate mode.
At the present time, I have a slight preference for the cheaper one (price and curve) but I’ve not decided yet.
What do you think?
If you have another monitor from another maker that could fit my needs, feel free to suggest.
Thanks in advance!

My requirements:

  • 23 inches or more
  • 144 Hz
  • G-sync compatible
  • less than 500 dollars
  • vertical mode if possible
  • curved if possible