Your best bet is to buy a good regular (smart) TV and then never connect it to the Internet.

The commercial digital signage displays are very expensive and not as good for normal home use cases.

There's some comments in this thread about the TVs "freaking out" if they aren't connected to the Internet. I haven't run into one where that can't be disabled, and I've messed with a lot of TVs.

Datapoint: my house is blanketed with recent-ish TCL and Samsung models and I don't have any issues with them. While they were much cheaper, I prefer the TCLs, if it matters. I have Apple TVs plugged into them.