I have used both the spirited shipper and the u-haul insert based boxes. I got both styles from previous beer orders but I am at the point of needing to order a new set by itself. I have never had a problem with either but I have used the U haul ones the most but they are 5 dollars more expensive per box.
http://www.uhaul.com/MovingSupplies/...g-Kits?mid=169
but with the uhaul boxes you get free shipping on a min of 2 while the shipping cost on the others are pretty high.