Tablet design

I am looking for someone to help build a tablet that is strictly for viewing videos and photos (media). In general, I have a few hardware and software specifications that I would need met, and I am hoping someone on here can help design a prototype for both the software and hardware. Essentially, think of designing a tablet that is meant to be secure enough for a prison. An example is that this device does not have the capability to connect to anything via Bluetooth or the internet, and nothing can be taken off the device once it is on the device (except if it is deleted).