[jacknews]

The current version looks like a great solution, because it's so basic.

You risk adding too many features (and cost) in the next version.

A cell modem is going to require certification and of course a separate sim-card/data plan. Do they need USB unless they have a computer already? And speakers? Is this to play the radio while tending shop? I'm sure even the most illiterate can still read numbers, so TTS would be just a gimmick IMHO.