I've often thought my Surly Pacer road bike would be a perfect bike for a coast-to-coast supported (or credit card) tour. I've gone off curbs and on gravel roads with it with no problems. It's a tough bike.

If you want to carry all your stuff a Cross Check or LHT would be great. If you are very short the CC does not go quite as small as the LHT or Pacer (check the geometries out).