I’d be happy to help with the migration if you’ve got a budget. You can post in Marketplace or see Discourse Migration - Literate Computing. (It seems like I talked to someone about Salesforce recently–apologies if it was you!)
I think my first import script (and I knew nothing about Ruby when I started) took a couple of weeks and I spent over a month on one that had some milllions of posts. Now I can usually write a good first version in a day or two.