Hi Antonio,
I am not with Laminar Research; just a flight simmer.
Serious flight simmers are using multiple FHD television screens to obtain the greater visual effects of X-Plane. Some flight simmers are moving towards 4K UHD screens but there are problems. I am rebuilding my system using 3 - 43 inch FHD screens for the out of cockpit view and a separate 24 inch screen for the instruments. From all of my research X-Plane is designed around the 1920 x 1080 visual (16:9 profile). Earlier comments in this forum from Laminar Research staff make this point in several locations. Television screens are far cheaper than large size monitors.
I had a look at the 49 inch ultrawide a few days ago in a PC supplier store. The experience was by being in the right place at the right time. Was not impressed. It provided a very narrow "slit" view for the "shoot-em-up" game it was showing. With X-plane you need good visual not only for out of cockpit view but also to see the cockpit instruments If you go the way of the ultrawide 49 screen you will be using the mouse scroll button more than flying the aircraft just to view the instruments. A pain in the backside. The cockpit view will be extremely distorted on the sides as you will only have a front-on view out of the cockpit. Any pleasure of flight simulation ie flying the aircraft, will be lost. From my visual experience with the 49 ultrawide and having a mental visualisation with X-Plane you will have a reduced visual experience.
Here in Australia what you will pay for the single 49 ultrawide monitor will be more than what you would pay for 3-27 inch monitors which will allow you to configure within x-plane a more natural cockpit (see the Michael Brown videos referenced below) or what you will pay for 3-40 or 43 inch FHD television screens as demonstrated in the Russ Barlow video found at https://www.youtube.com/watch?v=a7LfXqpi-I8 or https://www.youtube.com/watch?v=PjdgOBJ5xkQ The full Russ Barlow YouTube videos are referenced below.
Have a look at some of the YouTube videos which can be found at https://www.youtube.com/user/srbarlow/videos and also at https://www.youtube.com/user/col2mab/videos
This last reference is by Michael Brown. He has produced a lot of interesting videos related to X-Plane He owns a company that specialises in building PCs predominantly for X-Plane. Laminar Research recommends this company as the preferred supplier of a PC for X-Plane within the USA.
Hope this helps you in making a decision on the direction to take.
As a sideline issue, when you purchase X-Plane buy from the developers, Laminar Research, and support the work they are doing in creating X-Plane. The Steam version is a 3rd party product with no links to Laminar Research and slow to provide updates. The Steam version installation is slightly more complicated than the LR version
Good luck
Glenn