Are there any ETL tools that integrate with Rails models?

Question

I'm researching ETL tools to import flat files into a database and subsequently export xml files.

Many of the tools support generating code to use in your application; however, I haven't found any that support using code already in your application. Our model is complex (relationships, validations, polymorphic associations, callbacks, etc.).

What tools are available that will allow reuse of existing code? Or am I stuck recreating (and maintaining) my model in the ETL tool?

Note: My requirements for an ETL (as opposed to bulk inserts or activerecord-import) are the transformations. We receive data from over 200 different sources in a variety of formats, level of completeness, and cleanliness. Also, the "designer" most include is more realistic for the less-technical users who will be defining the transformations.