Elasticsearch to store account information


Just recently found ES when doing research about IR (lucene, etc). Seems like ES fits what I would like to do for a new project-- almost entirely. Would like to use it solely without the need to use another NoSQL DB or even a relational one since almost all of my data will have to be indexed and searched via JSON. I do have a question about ES though (or advice). Other than searchable data, I will have to store somewhere user account information (i.e. username, password, first/last name, etc). Now first thing comes to mind is a relational DB. But since this data would probably be relatively small and performance in terms of storing and retrieving is not a factor, could I just store this as is in ES? I mean I probably could but would like to know if this is not recommended, if there is a better way of handling this, etc. The account information will be tied to the searchable data, but that would be "copied" onto the documents themselves when indexed. What I'm interested in is the log in data.

Any advice would be appreciated. Thanks.