Hey, I moved my 120 gallon tank last summer when I moved house. The biggest deciding factors would be whether you are getting to the new place by plane or whether you are driving there (and how long the drive is). If you're flying and your tank is not long established and you wouldn't be heartbroken about losing your current stock, you can sell things and buy on craigslist when you arrive.
But for what its worth, here's what I did, keeping in mind I only moved about 20 min away:
-Removed all equiptment
-Loaded all live rock without corals/anemones on them into two XL (new) Rubbermaid containers, which were moved down to my car on wheelie furniture carts (purchased at Lowes for about 20 bucks) down to my car (no water in those)
-Pumped enough water out of the tank to fill my 5 gallon buckets (with lids, from Petco) 3/4 the way full with current tank water. Loaded live rock with corals/nems on them, and caught all the fish once the rocks were gone and put them in there.
-Drained the rest of the water down to the sand (tossed this water)
-Scooped out a few cupfuls of sand to seed the new tank and added it to one of the buckets with the water. Tried to get as many snails/hermits out as possible.
-Threw out the rest of the sand (scooped out and put in trash bags)
-Move the tank itself to the car/truck
So then you start out at the new place with a decent amount of water, and add new fresh water to that when you get there (oceanparadise's suggestion of mixing some water ahead of time and having it ready is a good one, wish I had done that)
I did not use any portable powerheads but like I said, it was a very short trip, so they were back in the tank within the hour.
Hope that helps! Let me know if you have any questions.
