S.B.
I agree with Tracie in that you need to be very careful with the company you pick for a long distance move. They can hold your stuff hostage! If possible, the best solution is to drive the stuff yourself and haul the car.
That said, one option we did on one of our last cross-country moves that worked really well is we "bought space" on a big truck - they drop off a big 18 wheeler trailer and you load everything in it and then together with the company you seal it up by putting in a big wall - then they take the trailer and load it with whatever goods are traveling across country and you arrange for a delivery date. This can dramatically cut your costs, as the process is designed to fill up trucks that have half loads. The downside is the amount of time you are without your stuff - it could be 2 weeks or so. I don't remember what we paid, but I do remember it was around half of a regular moving company. Then you can just hire movers in each city to load and unload.
Good luck!