I put in a Sealand and like it
It's a China ( porcelan ? ) Any way it doesn't scratch if you scrub it. The scratches will collect " stuff " and grow all kind of nastys. However, the seat and cover are plastic. Sooner or later, I will get a better seat at HD.
I picked Sealand because they offer a model that was low to the ground. I needed a short model because the toilet is sitting on top of the black tank, so a normal height toilet would end up toilet too high off of the floor.