from a Lithium perspective you can definitely post content in the community in a programmatic way, by using the REST API. Most of your requirement seem to be around the integration with the external third party to pull the data automatically: it could be that there are other developers or customers that may be willing to share their experience in this area.
Other than that, if required Lithium Professional Services can look into the specifics of your scenario, and determine feasibility / scope up a custom integration for your use case.
Hope this helps,
