This June I intend to fly to St. Augustine Fl. and take the ST until I meet the Underground Railroad, then take it to the Transam and ride west from there. This way I get three major areas covered, and the important part first.
So, I agree with others here that you can mix paths to custom fit your tour. Check out Adventure Cycle's site and you can see all the maps they offer. They have done a lot of your work for you.
Steven