I pay for Google All Music Access and it lets me get any song they sell normally and stream it as well as download it for offline listening. Has worked wonders for me. The only thing I wish is that my Android phone had the 3 audio buttons I miss from my iPod Classic: play, reset / go back a track, skip track. At least my steering wheel lets me do it...
This doesn't tick all of those boxes but in case you don't realise - in the last few versions of Android I've had installed I've been able to set a long press of the volume up/down hardware buttons to act as next/previous track. I can currently do it through settings/buttons but not sure how it worked in the past, it might have been app-specific
