Im looking to purchase a good quality pocket sprung mattress (double) for our 8 year old daughter (about 35kg) I'm looking for long term mattress purchase to last her a good few growing years. She has chosen a sprung slatted bed frame from OBC. I have been considering a John Lewis Essentials Collection 1200 Pocket Spring Mattress, and also a John Lewis Special 1200 Ortho Pocket Spring Mattress, or at the top budget the JL Natural Collection Hemp 4000 Pocket Spring Mattress. I believe the Natural collection is made by Spink Edgar and the Ortho by hypnos.Can you advise what comparable mattress you could offer, or shed any light on these mattresses. Kind regards