The only real way to KNOW if the surface finish is correct for Cometics is to use a profilometer. I don’t think anyone over here has one, and I don’t think anyone over here has a machine that is capable of machining a surface for a Cometic gasket.
I wouldn’t use either gasket. The small one is too small and the big one is too big. You are giving up compression and the crevice volume will make it very dirty.
Just my .02.
