I work in the shipping industry. We have a Synology NAS as a movie/TV server. We are currently using Samsung smart TVs (Tizen OS) to watch videos but, the interface is horrid and doesn't display any information or images and there's no search feature. I would like to run KODI for the UI. I need a device that uses ethernet that I can have on the network but block it's internet access. I would prefer being able to uninstall any apps that I don't need.
A raspberry pi would work nicely for you.