I'm sure that anybody who has Worked on a motorcycle for any length of time has had the words run through your mind… Build Your Own Motorcycle. Most people dismiss this madness immediatly but a small group of enthusiasts actually carry it through. Now we all know that there is not way we could build our own car, if we did It would most probbaly come in kit for from a manufacturer and just need bolting together. However a bike is different. You can source the parts from different places and manufacture the brackets and mountings to make everything fit.
The real enthusiast will sit down with a blank piece of paper and write a list of things to do #1 on that list will be Build Your Own Motorcycle Frame. Before you even think about something like this learn to weld, and learn to weld GOOD! those little welds will be the only thing keeping from a ride in a van with flashing lights and sirens.