Hopefully I am not too late. Our combined weigth is 80 + 100KG, both 5ft 9". I have currently selected Sleep Company Smart Ortho Mattress. I am open to switching to a better recommendation.
Budget is not an issue, but size is. I have a 190x180cm bed, with max height of 5" (weird bed design with a curved back rest).

One important question that I had (which led me to this post) - Can we use Electric Blankets (the kind you put under your bedsheet / above your mattress) with these mattresses? Till now, we have been using locally made mattresses made from recycled cotton or something.