Late post, but im doing it for the archives and google searchers. I have looked at every corner of the internet and spent 2 weeks nonstop looking at daybeds for my guest room. Birch Lane (higher end brand of Wayfair) is the ONLY strong solid wood day bed I found w trundle (unless you spend $$$$ w an Amish store). The SKU is CDCH1056. It's weight capacity is something like 700 lbs for the bed and 300 lbs for the trundle. Pricey at around $8-900 but again, it's the only bed you can find online boasting that weight capacity. Everything else is flimsy fake wood. I also liked that the bed can take 10" thick mattresses while the other flimsy daybeds only took 8". Good luck More on reddit.com

I would buy a base secondhand locally and then spend the majority of the money on a new mattress. Also if you buy a wooden base you can store things in boxes underneath, you don’t necessarily need a divan unless you prefer the look. More on reddit.com

If they are a couple, ask them. If they aren't in a sexual relationship twin beds. More on reddit.com

Sounds like you need the Japanese futon life. No frame, so there’s no weight limit. Just two futons, when not in use you fold them and stack them. More on reddit.com