The biggest problem with iPads in retail is that people staff, and customers steal them. As such what you need is some way of protecting them. Here are some cases for iPads, I saw in Denmark to do this.
We have had a client that had the cable holding the iPad ripped out, so it certainly not a complete cure.
The other problem is they can still be dropped. When this happens the glass in the front sometimes cracks. Unfortunately, this is not covered under warranty. The problem is that the iPads are extremely difficult to fix. I consider this to be a major design flaw which I am sure is deliberate.
If you do intend to use an iPad in the shop (something I system allows) I recommend you copy the serial number and keep it in a safe place. You will find it at the back of the iPad. Use that one not the one in the box.