I miss the times where you could really feel the speed of the remote while you browsed through the channels. Feels like emulated, bloated and slow to interact with TVs nowadays..
Absolutely do not cheap out on this, this will have to run for some time without hiccups. Make sure you've got a digital signage supported TV such as NEC or Samsung that supports 24/7 operations. NEC even offers a built-in Raspberry Pi which is awesome. I've implemented over 400 NEC monitors for 24/7 ops and it will stand the test of time most cases even for 10 years.
These kind of TVs have low-glare and the picture will not burn into the monitor while providing enterprise security. Samsung do offer digital signage approved TVs as well.
If you choose RaspberryPi just know that it usually uses an older version of Chromium. Other devices might not have a modern browser so all of your fancy code wouldn't work.
I've got some good experience with Yodeck and Screenly. Dakboard is also pretty cool as it offers you to directly fetch data via REST API calls.
I've used Dakboard and Yodeck together to be able to quickly implement custom dashboards to dozens of TVs