Remote management of playlists

We're investigating a high-tech way to do a project that involves streaming music from a playlist that's updated monthly.

The iPod would be in a dock and on 24/7.

The playlist can be paired with any of the popular online radio apps. Will be trying Spotify and Pandora first, but I'm up for anything that is simple, easy, and has a good music selection.

The goal of the project is to have a one-button playback. Any time, day or night, just press play on the dock and music will play.
That is all I need it to do, but we'd like the option to manage the music remotely as we are a few states away and need a reliable system that works for when they want new music.

I can put the iPod in Single-App mode if needed using MDM profiles, but the main thing is if the app crashes or goes to sleep, will pressing play on the dock activate Spotify/Pandora each time, every time? (If not, is it possible to make it so?)

I'm open to sound dock suggestions and apps.