Indeed. Understand that for each channel they want patrons to watch they'll need a channel of modulation. They'll need a cable box tuned to that channel, permanently, connected to the modulator.

The displays will need to decode Qam channels.

For a small place, way too expensive. For a large place, a tough choice.

My favorite supplier can lay this out for you. There are lots of additional things to think about, and frankly, don't want to waste your time if this is a generic question..