It seems that a missed this late last year, but apparently Noctua have released a new 60mm fan. This is significant because it will fit in the FAT ps2s without having to 3d print a whole new back panel, you instead just need to print a mount for inside the case. I have personally never been a fan(no pun intended) of fan mods in general. But if I was to consider one, this would be on the radar for sure
There are a few different versions of this new fan, some of them being 12v and the others 5v. The consensus seems to be that a 12v is required for adequate airflow for the PS2. Also, additional circuitry is required to run the fan. It would be good if someone made a kit with the additional circuitry and the 3d printed mounting bracket, but that does not seem to have happened as of the time of writing this. You can read more about it here