Question 144 Hz 1080p Monitor for competitive gaming

[nxnje]

Hello everyone.
After building my new pc (I still didn't buy a GPU but I'm gonna do very soon) I wanted to buy a new 144hz screen.
As I do not know if I'm gonna buy a rx5700xt or a 2060s/2070, I would like to buy a freesync monitor which is G-sync compatible as well, even looking for the future as I do not know which will be my future upgrades.
My decision just went on 3 monitors:

• AOC 2590FX
• AOC 2590PX
• HP 25x

I'm more on the 2590FX for its price, but I'm also considering the other two.
Two questions:

1. which are the differences between 2590PX and 2590FX? Been searching for a while on the web but I've just found someone speaking about a pivot screen vs fixed screen, but I do not know what that means. Hope somebody can give me some more informations.
2. In your opinion is it worth buying one of these? If there are bettere choices around 200€ , I'm open to advices.

I'm buying from Italy. Budget 180/200€ , I can reach 210 but I'm already extending too much.

 

[freercurse]

pivot/fixed basically when a monitor can pivot it mean it can gimbal a little bit up/down/left and right.

 

[nxnje]

pivot/fixed basically when a monitor can pivot it mean it can gimbal a little bit up/down/left and right.

You mean that pivot screens can be inclined and moved while fixed always stays perpendicular to the desk?