The models resource
The models resource is a perfect website to find models from existing games.
You can sort by game console or you can sort by game name. There consoles from the Dream Cast to the Play Station 5
You can download the models as OBJ files and use them in 3D software like blender. Although these models are free to download you cannot use them in a professional render as they are protected by copyright. They are perfect for understanding how achieve a PS1 style as these are actually models from PS1 games.
By downloading the model you can see how the image texture looks and it is UV unwrapped.
DBOOTH