I did some digging about what sorts of beds can be used for teardrop trailers. I'm attaching a link to my website. Scroll down the FAQ section and look for the question, "Does it come with a bed?"http://www.boondockcampers.biz/#header_faq
The answer section contains a download link to a PDF spreadsheet that shows my findings. Hopefully it helps out some shoppers!
Full Disclosure: Yup, I build and sell campers. You will have to enter my website to obtain the spreadsheet. You have been warned!