Help choosing a foundation for traditional wooden bed frame

Hi all, I just purchased a new-to-me bed frame and need some help finding the right foundation.

I bought a used bed frame on FB marketplace that I think is designed to be used with a traditional box spring. It’s a mission style wooden bed frame that has three slats, with a foot at the center of each slat. But it has no siderails or ledge of any kind that could be used to hold additional slats, roll out slats or a bunkie board.

We need to add a foundation of some kind but we have a very tall 14" mattress and I’d like to avoid adding too much additional height. The mattress is a NovaForm ComfortGrande Advanced 14” Gel Memory Foam Mattress.

Does anyone have a recommendation for a 2-4" foundation or solution of some kind?

These are what I found with my own quick, amateur search…

Zinus Walter Standard Profile Metal Smart Box Spring 4" with Wooden Slat Support

Hello and welcome to the forums and thanks for reaching out on this! We have a 1.75" bunkie board on our other website here - Bunk Board - Mattress Foundations

It’s an outstanding product, no harmful chemicals, organic cotton cover, holds up to 1,200 pounds, made with #1 Spruce furniture grade wood, and has many other benefits, so I think it’s worth checking out!