It's been my experience when helping friends move or even moving fish from one room to another that the best way to move the tanks is empty. They can get beat up real fast even with only a little bit of water in them. Sloshing around in a car doesn't help matters. There isnt much that will test your seals faster.

If you can get a few plastic tote boxes - whatever size you are comfortable with, you can move fish, gravel and even a good deal of water in those. Make sure you get them tall enough that you only have to fill them partly full. They don't tend to seal real well. Putting towels around them is a good idea as well. Before you use them, make sure to rinse them out real good until the plastic smell is gone, but do not use soap. It will kill all your good bacteria. I also only use new tubs or tubs that have only been used for fish for the same reason.

Someone I know had a 150 or so gallon monster that needed moving. All the gravel was put into 5ga totes with just enough water to keep them wet (he liked working hard I guess since he filled them almost full). Fish were moved the same way. It gave them plenty of room without straining the tank. He also filled several with water and left them in the back of his pickup to slosh around. Once the tank was empty, he toweled it out lightly, wrapped it in old blankets and we moved it directly to the new house where it was setup and running in no time with all the fish alive and healthy.