Hi,
Why not build your own? You can then replace items/layers as needed when the foam topper layers break down as they surely will if you go that route. I contemplated building my own for a couple years and I’m so happy that I did. You can read my DIY build story at https://forum.mattressunderground.com/t/feedback-on-first-diy-build/34745/8.
Of course you would need to adjust for your much lower weight and also the softness desired.