This is what I did. I used 1x2 material from lowes, it's around $1 for an 8 ft stick and comes in 6 piece bundles. This side is my sons side and I took apart an old bunk bed box frame and cut it down for him then reused the old foam mattress.
This is what I did for the gaucho side. Same basic frame, just reused the slides from the gauchos and bought a new spring filled futon mattress from the local furniture store. It's a little wider when pulled out, so I made some supports to hold up the wild end.
If you notice I planned out to make flip down doors for storage access under each side, not messing with the old broken down tambour.