Welcome to the forum, Mike. You are not alone, with your concerns about your proposed teadrop style, shape and exterior materials. There are so many potential shapes, sizes and quality of materials, that you have to choose from. I suggest that you pick out the ideal teardrop configuration to suit your liking, and press on from there. Good for you, choosing to build a woody. (Being a woody owner, I can relate to your feelings). However, since we don't know where you are located, (lots of snow during the winter, lot of rain during the wet season, or being able to live in a relatively stable, teardrop friendly area of the country) your exterior material, may be in question, perhaps you can enlighten us, a bit.
Hey, if you can read plans, build R/C airplanes and are willing to alter existing plans to suit your needs, you are on the right track. I think it would be a good idea to pick and choose which shape and style would fit your needs best. No one has to follow a set of plans exactly, that is what makes our teardrop building so unique. It is a joy to crank out a neat, individual design, with all of the self-imposed requirements that only suit the one-and-only builder.........you.
So, check out the various sites, listing different plans and sizes. I think that a 5 x 10 is probably the perfect size, noting the size of your family, kids and grand kids. Keep the dream alive, and make that committment.
First step........obtain a suitable trailer frame! A 4x8 would work for you as you can extend the width and length of the wooden trailer to suit your needs. The shape and design is up to you. Your personal ideas and designs will soon take shape, and the ultimate result of your build, will please you well into the future.
Remember, those of us on this board, are here to help and all you have to do is ask questions and you will be amazed at the help you will get. Keep up effort going, get that trailer frame and get started as soon as you can. Who knows, we may be sharing a campfire with you sometime in the near future. Good luck on your build and remember, pics, pics, pics.
PS, where are you located, here on our globe?

Roly