I bought this twin mattress for my teenager. It has created make better sleeping experience over the previous mattress. https://www.amazon.com/Mattress-Box-Pocket-Innerspring-CertiPUR-US-Comfortable/dp/B07M9N93XB/ref=sr_1_2?keywords=dikapa&qid=1559766119&s=gateway&sr=8-2
Tag: vendor
Latex mattresses and toppers https://sleeponlatex.com/
Link to latex toppers on Amazon https://www.amazon.com/s?k=latex+topper&ref=nb_sb_noss_2
Custom Foam Vendor https://www.foambymail.com
The Banana Test
This website can show you how to fix your sagging mattress and sells components to help fix it. https://diymattress.net