Rubbermaid Totes also work well, especially for Live Rock pieces that don't always fit well in buckets.
Whatever you use, pack it in your vehicle so it can't tip over or it will create a real mess.
I agree with Tourkid, have at least 50% new water prepared and up to temp. You may want to have more than that if you can store it.
Tourkid did a writeup of her move on here, if you search her past posts you should be able to find it.
It had a lot of good info.
I would plan for this to be an all day event. I would do ti on a Saturday so you can finish up on Sunday. Plus it is easier to find help on the weekends usually.
I have a 30 gallon trash can I use to mix water in you can borrow. I also have two Styrofoam containers that work well for livestock (lined with plastic bags).
Good Luck,
Ken