From your list, I would go with Debian. Fedora is amazing but doesn’t have LTS, so you’ll need to update it manually quite often. You can use a script for automatic updates, but I rarely had it working smoothly. Ubuntu is just a joke with repository hell. I wouldn’t recommend it to anyone but grandma or a child for the desktop, because of its simplicity. TrueNAS never tried…🤷

I would also look into Alpine and some Arch-based distros.

And yes, use containers, this will save you time eventually.