Looks like plenty of good advice already given. I would personally start with the organization with whom you want to compete in scale with. Every competition is a little bit different in their requirements, i.e. documentation, static judging, flying requirements, etc. Because human objectivity is involved in the judging, there is no such thing as only one plane or one kit that is capable of winning all scale competitions. Like everything, scale competition is a learning process which takes patience. Learn as you go. Good luck!