Hi MW,
The Seven Comforts topper already has an unbleached natural cotton cover around the latex so all that you would need above this would be your mattress protector and your sheets and bedding.
FWIW … I just “stuck my nose” in the Seven Comforts topper to see if I could smell anything and there is a very faint smell of rubber but I certainly couldn’t notice it unless my nose was right in the topper and it’s not in any way unpleasant.
Edit: see post #52 here first if you are considering ordering this topper.
Phoenix