I need to implement custom DMS system based on SharePoint online and Azure Blob Storage. I want to use BCS with oData service implementation for Azure Blob Storage. Client need to work with larger files in more geo locations.
Any suggestions, or any better tip/hint?
Your solution holds good. But how much documents (total size) you are looking to store. Storage is much cheaper even in O365. File size limitations are also increased. Also you need to check the O365 CDN option which is made available recently.