I picked up two of these cases from Michael's, a franchise of craft stores here in the States. The cases were only a couple of dollars each and they seem to work perfectly. Now I must admit that I have not actually used them to transport the minis yet (what with the holiday break in gaming for me) but they seem to be perfect as you can see below.
I also have a unit of Therian Assault Goliaths which needed a home, but they are a too tall to fit in a regular compartment. If you look at the upper right side of the organizer you can see that it is actually a double sized compartment, which made it perfect for an Assault Goliath. One of them. The good news is that the plastic that the boxes is made from can be cut with a utility knife, so I simply cut out the dividers on the compartments next to the original one and now Larry, Moe, and Curly are all safe and sound in their own little cubby holes.
As you can see, all of the regular sized minis fit in perfectly. They have a little wiggle-room in there but if you are really worried about breakage it would be easy enough to put some kind of padding in the compartments to keep them from moving around.
The larger minis (such as the Fire Toads and Golgoths) are not quite so simple; aka I haven't found a good container for them yet. Then again, right now I only have the one Golgoth so it is easy enough for me to simply have it ride shotgun with me to the store; aka I haven't actually been looking for a good container for them yet. Once I find something though, I'll be sure to pass on the good word.