It has been a year or so since this topic has come up and rather than folks bUy bogus plans off the Internet, here is a reputable reference. Randy and I used the builders manual from Steve Fredrick extensively in our build. He describes building from the inside out, how to make honeycomb walls for weight reduction,build the hatch and even a door seals method and how to epoxy. I would never have tried it without this manual. It does not give plan, but rather is a construction how to guide. You can draw your own profile and go from there. We shared it with friends and they have found it helpful as well. Dave of the Atma travelear used it as well. ( in addition to his massive artistic brain). Anyway, newbies might want to check it out here.
http://www.campingclassics.com/index3.html