Unfortunately the way the HN API is designed, it only returns IDs and you then have to make a separate request to get details for each of those items. We recognize how limited that is and intend to make a new version of the API. In that version, you'll be able to request a JSON version of any page and get all the info that's on that page. I think this will do what you want, or at least will easily be extendable to do it.
That would be great for anyone who tries to build an API client, whether for reading or analytics such as the OP.