I am investigating a solution for storing millions of documents in SharePoint 2013. Almost all of this will be TIFF images and HTML files that are currently in a file system. There are some indexing metadata (e.g. customerId, creationDate etc.) for each file in a DB. One part of the job is to migrate all the existing documents and the metadata in SharePoint. The other part is to use SharePoint (after migration) to programatically store new documents and add metadata as they are created using a backend service which receives these documents from an external source. Programmatic searching of documents by metadata (and in future full text using OCR is desirable) is must. There is also a need to tag documents (different to structured metadata) as well. The documents will be retrieved and displayed using a bespoke ASP.Net web application and SP will only be used as a document repository. The end-user is not intended to directly use SP.
Being new to SP architecture I am looking best solution options to achieve this. My research indicates storing documents on the file system using remote BLOB storage seems a good option.
My question is RBS the best option for this or are there better alternatives for my need.