MySQL or Mongo given need for relational analytics

Hi, I have an application that is primarily a straight-forward web application but the data is very relational in nature. If I wasn’t using Meteor I would definitely use SQL. However I want to use Meteor because there are a lot of screens that seem like they would be very fast to implement in this platform and there are definitely some areas where reactive programming would be good for voting, etc. I also need to plug into some reporting engines down the road that will only report on SQL dbs unless you know of a BI tool that works well on Mongo data?

So I think my options are use some SQL package and handle all the interaction myself, use mongo and simulate the relationships where needed (there are a lot even if I rearchitect to be more mongo friendly.) or some hybrid where I sue mongo for some and sql for other parts or one other option is build the whole app using mongo and then for the reporting components have some sort of translation into a SQL db (in the background).

If you do think I should go the SQL route do you know a preferred mysql package or possibly an ORM?