b1if b1isn or b1ic for integration with other systems

I don't fully understand the different integration types and the difference between b1ic and b1if.

I want to create documents in B1 from text files - not xml - from other systems and create text files for other systems in response to B1 events and with data from B1 documents.

Which, if any B1 integration technology is most appropriate for this and which layer of the technology would I be working with. Would I expect to be defining processes with code or with an external application that I use to interface with the integration technology?

Are there any documented examples of this king if integration?

Thanks.