Office 2016 beta on Mac
Office 2016 for Mac has a stable release available for Office 365 subscribers. It'll be available as a standalone purchase at some unspecified date in September. Until then, it looks like Microsoft has taken their beta down. What you could do is wait as long as you can bear to live without Office and then sign up for a free trial of Office 365, and then unsubscribe and buy Office 2016 once it comes out in September.