As with all these projects it is what the person building it brings both in the vision and capacity to build that guides the project. I have been following blogs on cargo trailers for the last two years. I don't quite understand the "haters" who have to jump in and correct someone else's project so be nice and I will gladly respond. I would love to hear about your project as well.
Here is a shot of my little solar generator. I am currently charging it on 110v but once the weather changes I can get some sun in my life and do it correctly.