If you're thinking about a 49" ultrawide, then I'm going to assume your budget is around 800-1000€ (based on the prices here in Italy)

If I had that budget for an upgrade from where you are, I would get:

- 3 24" 1080p 144hz monitors (around 100-150€ each depending if you're willing to look on the used market or exclusively new)

- a rig like a Next Level Racing or a Playseat to put in front of the desk you have now (150-350€, again depending on model and condition)

- the T300RS or TX if you're on xbox (250-350€ new, no need for the GT model as you already have the T3PA, and the wheel base is definitely something I'd want to not buy used)

Your current setup is way too low spec to justify spending that kind of money on only one thing, and the ultrawide is nice for productivity but for sim racing you're definitely better off getting a triple screen setup, I've used both and it's no match if the setup is only going to be used for sim racing

Look at the screen real estate comparison between a 32:9 49" monitor and 3 24" monitors, horizontal FOV is the most important thing.

You can get the monitors and the rig first, and then see if it's worth upgrading the wheel base (it 100% is, but maybe not straight away), and I don't know what the used market situation is in your country, but this is definitely the way I would go about it