Typically white filaments are slightly abrasive. Since you will be coating it anyway, I’m not sure there is an advantage. Also, consider the orientation in the slicer. If you orient it with the concave surface (inside of the sphere) facing up, all your supports will be on the outside, where it should not impact the interior surface. If you are going for a smooth surface, use Bondo, or other filler and fine sanding should get you to the surface finish you want.