It depends what forum you were using before... we have specific exporters for most of the major forum software platforms.
If it's custom then you're looking at having to write your own or contact us at email@example.com for a quote.
I was at a mongodb meetup in Dublin the other night and they did a presentation on their mongodb management service (I'm not actually sure that's what it's called). Anyway, it's awesome and worth checking out, so I figured I'd mention it: https://mms.mongodb.com/
If you are on AWS, you will mess yourself when you see how simply you can set up a sharded cluster with replica sets.
ObjectRocket is pretty keen as well.