I can pass along the guys name if youre interested. He has a lot of good military surplus boxes.
If you want your young children to be able to get into the cases, go Storm. If you want to make sure they can't open them for a few more years to come, go Pelican.
OK, I got a little nervous when I first read this post. Put the kids in the cases and then make sure they can't open them???? Whoa. I had to read it a second time very carefully.