What sort of mattress topper for a latex mattress?

Unfortunately John Ryan don't deliver outside of the UK so I bought a Dunlopillo Latex mattress. I'm wondering what sort of topper to put on it? More Latex? I know you always recommend a topper and usually one that matches the comfort layer but not sure if this still applies to latex. I'm concerned about protecting the mattress but don't want to make it any softer.