Come up with 20 bucks and get it from the source ?

I use a Kindle Fire 7in I picked up for around $39 for my roof solar system display (next to my Dakboard). Should do the trick fine even without jailbreaking. I run it 24/7 to access my systems URL, and they usually last a couple years before they get the black screen of death then I just replace. Very little power usage, and if you enable developer settings, you can set them to maintain brightness, ignore under powered USB adapters, etc. I stuck it on the wall with gorilla tape.