Buying a new bed but which one?

I want to purchase a king size double bed. I have laid on and tried Vi-spring, Hypnos and Millbrook Boutique 3000. Have been advised at Furniture Village that the Millbrook is the equivalent quality to cheapest Vi-spring. My husband prefers a medium support where I am comfortable with soft . Husbands weight is 13 stone and mine is 10. I want a natural fill mattress. There is so much choice and would appreciate any advice.
Thank you.