We are in the process of finishing the redesign of our NFC reader. It will use a Bluetooth interface instead of the Audio jack to communicate with the Host device (eg iPad), yet maintain the same 40mm circuit board size. Since we don’t command enough volume we won’t be making custom cases but you could easily dremel out some space from an off-the-shelf product (eg Otterbox) and epoxy in our circuit board with battery and all. This will give you a robust and usable prototype for you to test out in the field. If you can get an order of 1000+ units, then it makes sense to create a polished case for your application.
