As far as the fueling is concerned, I would use truck stops and you can get frequent user cards to help in some of the costs. I am a member of Flying J and when travelling I get the "cash price" when I use my Visa with my frequent fueler card at a Flying J. You can get their locations or any other brand X locations on the internet, to help figure your fueling stops.
Good luck with your trip, are you going to the Phoenix NASCAR races?