Calendar Options?

I'm moving from Outlook to portable open source software for my organizational needs. I've gotten Thunderbird up and running with GnuPG support. I've cleaned up my address book, after importing it from an Outlook pst file. (I'll be adding head shots this week, copying them from my work computer.) My email provider is gmail.

So the next thing I need to move over is some sort of Calendar. I currently use google's cloud calendar. My work calendar is synced onto Google Calendar using Google's sync program. I also have a couple of shared calendars I use (rehearsal schedules for gigs, etc.) as well as personal calendar.

So I'm looking at my two options: Lightning and Sunbird. According to Mozilla, Sunbird is being phased out in favor of Lightning. But Lightning is still at the beta stage.

Should I wait for Lightning to be ready for prime time, able to sync to multiple google (and other) calendars? Or is Lightning actually ready for prime time now? Or should I use Sunbird instead and give up on Lightning? Or should I do something else?

Any thoughts would be good.