Both times I've had to move my tank, I just used the 30 gallon, Steralite containers from Big Lots. They aren't water tight, so I only filled them part of the way and was careful to keep them steady during transit in my car.
Walmart has 5 gallon buckets in the paint department, and they also have lids. Last time I got some, the buckets were only $2.50 each. to my knowledge the lids are free
I was going to suggest the 30gal or bigger from big lots. i have moved some big tanks and they were invaluable. You will not need them since you are just moving a 55. you can probably put half the water in 5gallon jugs and fish and some more water in a bucket(remember to take the water out before you go stirring everything up, this also makes it alot easier to take out rock and catch fish). Get rid of the remaining water. That will give you plenty of the old water, just have some new water made up for when you fill it back up. you might as well do a water change while you are at it. Put the rock in another bucket and in a 55 gallon you can probably move it with out taking out the sand. I recomend putting an air pump in with the live stock while you fill up the tank and stack the rock.
Dollar store, big lots, and wallyworld are your best places to find them cheap. Even rubbermaid containers filled partway are good for liverock and sand. Fish you can bag individually (sometimes people at Petco are nice enough to let you take some home for free) and put in styrofoam coolers.
We use Ice chest to move rock, coral, & fish. Everything has gone great so far! When your done all you have to do is clean out. we have also used tubs from Dollar General.
Other than that I have salt buckets w/lids. Your welcome to. There should be members on your side of town that have empty buckets.
Fish boxes are the best in my opinion... contact a LFS and see if they will hold some from deliveries for you or sell them to you cheap. I know frank goes through a ton of them but hes a bit far for you.
We should have a stash of these strategically located around the metroplex