It sounds like Business Essentials is a good fit, it gives you a 50 GB mailbox with your own domain, 1 TB of OneDrive space and Lync Online.
If you stepped up to the Business Premium plan, it includes the above plus "Office ProPlus" which is a subscription-based version of Microsoft Office (still locally installed) which is licensed to be used on up to 5 machines. Today Office ProPlus is essentially Office 2013 but eventually it will become the next version of Office whereas a traditional Office 2013 installation will need to be upgraded. Business Premium also licenses you for the mobile Office apps.