It would be much like a rasberry pi wallet kind of device, except on a more robust odroid board.
Since NXT is a web based wallet, it would be accessible via this device if you plugged a monitor/mouse/keyboard into it, as well as would be accessible to any other computer you have on the LAN of the device.
I can whip up more documentation as necessary, but am trying to gauge the interest before investing the time it would take to get a standard img ready.
Yes, I'm currently using jnxt.org/vapor
Downloaded the html to my raspi, done.
Now I have a cold hardware wallet
edit: blackyblack1 is working on making a trezor that works with Nxt.