Is the house occupied? If not, can the existing floor/decking be removed to get direct access to the crawl space and supports? If so, that will make the job so much easier.
While you are at it, have you considered digging out underneath the house and creating a concrete and cinder-block basement? It would cost a bit more but since you are already doing major foundation work, it might be worth it and would dramatically increase the square footage of the house. Adding a basement would allow you the freedom to bring in large excavation machines to do the digging with.