Hi Kelvin, welcome to the forum. I suggest you try to visit a teardrop gathering, soon. You will get tons of ideas, meet many helpful folks who can steer you in the right direction. You might do what many of have done, and that is to build a scale model out of cardboard, just to see what fits where. Some have even cut out a full-size cardboard profile that can be altered much easier than the final time-consuming profile.
This board is a wealth of helpful information, check out the Hall of Fame to see what shape, size and width fits you needs. Do ask questions, take pics of your progress, (we love pics) and jump right into the wonderful life of teardropping. Good luck on you build, many of us have been exactly where you are, and be aware, that this little camping trailer will probably change your life.
Roly, an old-time woody teardrop designer, builder and USER!
