I am disabled an am looking to replace my K/S mattress with nothing higher than 55cm. The mattress that I want to replace is firm - ortho. I want a smooth surface finish, not buttoned/tufted. I do want pocket sprung and a mattress that can be turned and top to tailed. I prefer not to have any type of Latex or foam. I am 5' tall weight approx. 11.7 stone and sleep alone. I have a divan base but know I will have to be prepared to replace this to get the right height. An approx. cost will be appreciated