I bought this on Amazon recently. The matress comes in a vacuum-sealed bag and decompreses as soon as you open it. They have versions with either springs or memory foam. I got a full, but as you can see they have other sizes.

http://www.amazon.com/Signature-Sleep-Contour-Inch-Mattress/dp/B004LQ1RJ2/ref=sr_1_1?s=furniture&ie=UTF8&qid=1424459374&sr=1-1&keywords=mattress