Hi Patropolis,
I’m not sure who you are dealing with but it may be worth doing a forum search on your local supplier just in case they are mentioned on the forum.
You’re probably not the only one that has become friends with Alice 
You may have read this already but just in case post #2 here and the topics it links to has much more information about mattresses and children that may be helpful as well although it sounds like you are already considering some good quality choices.
Phoenix