Replacing a back bed on our Bambi

[crystallady]

We need to replace the back mattress on our '04 Bambi. My first thought was a simple memory foam mattress, but I read on 'Forum' that someone used an IKEA mattress with the memory foam...but I'm not finding the post, argh.
If someone knows about using the Ikea mattress please let me know which one/type you purchased. Thanks