I’m pretty sure Volumio supports Spotify as it says so right on their frontpage. I suggest you ask in their forums how to use it if you don’t understand.
I personally have no experience using a touchscreen with pimusicbox. It can be done, if you search on here (always a good idea before posting on any forum) there are existing topics regarding using touchscreens, such as Anyone use the Mopidy Touchscreen Front end?. Sorry, I can’t really help with this.