For that long of a trip I would suggest properly bagging all of the animals, packing the bags in styro coolers, and if the temp is cold, you can pick up heat packs to tape to the inside styro cover. http://industrialsavings.com/Merchan...e=warmingpacks
Check out the heat packs I found online, these are the kind I'm talking about using. You can find them in most Walmart stores in the hunting/sporting goods section. These work great so long as they don't come in direct contact with the bagged animals... I use packing tape and tape the edges of 1 - 2 of them into the inside cover (after activating the heat pack) so they are secure. The size and number of the heat pks used is determined by the size of the styro cooler being used.
If traveling by car and not planning to make any stops, you might want to warm the inside of the car up before leaving, put the animals in styros as described above, and go from house to car to house. So long as they are not left to sit in a cold car unattended, they would be fine.
The trick is going to be in bagging them properly. The most common mistake I see made when bagging fish is that people blow into the bag once the fish and water are inside, to inflate it before closing it up. Please don't blow into the bags!
When you blow into the bags you are putting carbon dioxide into them, not oxygen, and you can easily kill your animals this way. The best way is to carefully set the bag of water and fish onto a hard solid surface, holding the top open as far as it will go to capture air. With a swift grab, close off the top of the bag tightly and twist it slowly down, leaving yourself enough of a "tail" to fold it over and put a rubber band securely around it. It may take a few tries to get it right, so I suggest working with just a bag of water with no animals the first few times you try it until you get it right. Do not fill any of the bags more than 1/3 full of water. Because some corals can be air sensitive, it's a good idea to submerge the bag and insert the coral before lifting the bag out of the water, so the coral never comes in contact with the air while moving. Once moved, and acclimated properly, the same method in reverse works for putting them back into the tank.
One other possible option for you: If making a direct trip without stopping, again, preheat the inside of the car. The fish can go into covered buckets, but you don't want any bucket more than 1/2 full of water and you'll want to use a battery operated air pump, with an air stone attached to the end of the airline tubing. Drop the air stone into the water to keep the water circulating and oxygen levels sufficient during the trip. Again, directly from house to car and then car to house, so long as the car is warm the whole time, you should be ok.
For moving the live rock and sand safely... sand can stay in the bottom of the tank, wet but not puddled with the water that has been drained. Save as much of the water as possible in buckets to refill the tank on the other end. Ultimately you can expect to lose some water content, so be prepared to fill the tank with fresh premixed salt water. This will act as a water change which won't be harmful to the fish or cause a mini cycle to happen. Once the tank is refilled, run the heater and bring the temp back up to 76 degrees before adding the animals back to it. Meantime, the animals can stay "packed". If done quickly, this should not take real long. Once the water temp is at least 74, begin acclimating the fish slowly, as if bringing them home for the first time, and then put them into the tank.
For moving the live rock, again styro coolers work well... you may want to put them inside of cardboard boxes for added strength. Place wet rock into the styro, take some newspaper or paper toweling and cover the rock, then pour enough of the tank water over them to soak the paper completely, but not to pool the water in the styro. Do not dip newspaper into tank water that is intended to be saved.
Crabs and snails should be bagged seperately, by themselves, and treated the same as fish. Crabs and snails can go into a bucket like the fish, but I wouldn't mix them into the same bucket as the fish or corals, or with each other.
One - 2 fish per bucket would also be a limit, if bagged, one fish per bag.
If there is more we can do to help, let us know...