Is there a perfect King Size Mattress for overweight persons?

Have purchased 2 King Size beds in last 2 years and hate them both. The first was memory foam.... hurts the lower back...can't move feel suffocating. Next was a firm pillowtop which broke down in less than a year. One person is 350 lbs and other is 200 lbs. We love our Queen Size serta in the guest room but King Size beds seem to be a horse of a different color. We tried expensive thick feather quilted pad which helped for a few months. Hubby says must get a new bed today!

Is there any way to get the same type of serta mattress you like- but in a queen?

You probably already tried that, but there is a link to an article from a mattress salesperson that says that heavier people should buy the top of the line model.

I wish I could give you better advice, but I am still on a darned futon.

Room Solutions 4" Gusseted Baffle Box Featherbed-King