I currently have one Sonos and several of the Cheap Sonos connected. I started with the real Sonos first and it did work well, I am very happy with it. We are frequently in our family room in the basement and I use it mainly for notifications for the arrival of family members and a doorbell (kind of) it notifies when the sensor on the screen door opens (good place to start). I have not explored the custom options yet but I have done some reading and it seems possible by adding some code and hosting the files somewhere you can access them from like google drive (I got side tracked with the cheap sonos about this time and thought it would be more beneficial).
I have one of the Cheap Sonos connected in our bedroom playing a relaxing music station from Radio Tunes with the wifi dlna music box (it had a different name at the time I purchased it, seller has changed the name, looks the same though) using the code here.
Additionally I am using an old cell phone connected to PC speakers running with the android app Private Dancer, which plays a convincing barking dog sound when visitors trigger the motion sensor on the front porch.
I have not really played music through the smartthings app outside of what I have mentioned, I do not think it gives you the ability to “browse” for music, I think it only lets you play/stop/rwd/ff music from what is already been playing, requiring it to be accessible all the time, like streaming or something on your network that is accessible all the time.