I am also in the early planning stages for a similar trip in July. You may find some helpful information here.
http://www.bikeforums.net/touring/10...ggestions.html
Keep in mind that in addition to the national routes, there are regional and local routes. I'll be making some decisions soon as to flights and itinerary, and will update my thread when there are updates. Right now, mainly focused on getting my travel bike frame in my hands and built.