Do you really need all your music on your tablet, or will a few playlists suffice? You can still use your iPod Touch after all. If you are willing to move content on and off your tablet you can certainly manage with 32 or even 16 GB, since the tasks you describe using your tablet for are not data intensive.
You are really choosing between operating systems, so you should check whether or not the apps you have/want are available for tablets on the Android platform. Are you going to have to jump through hoops to use your calendar or other apps that would easily sync if you stayed with Apple? What's your comfort level with learning a new platform?
I went with the iPad mini in the same situation (already had an iPod Touch). Since I also had a Macbook Air, it was a simple choice to stay with the Apple, so that all my existing stuff would sync between my devices and because there were a few apps I use that are Apple only.