Which version to buy?

I’m trying to import a drupal database for a client. I’ve not used drupal before so not sure how the data structure goes, but the import log says:

`[WARNING] Your Drupal database contains users. You need the Premium version to import them.
[WARNING] Your Drupal database contains custom nodes. You need the Premium version to import them.
[WARNING] Your Drupal database contains custom taxonomies. You need the Premium version to import them.
[WARNING] Your Drupal database contains URL alias. You need the Premium version to import them.
[WARNING] Your Drupal database contains navigation menus. You need the Premium version to import them.
[WARNING] Your Drupal database contains forums. You need the Premium version and the Forum add-on to import them.`

All I want to import are the articles, some of which the client says he has set up as a specific content type, with a form designed to add them. It imports the static pages with no problem.

So what version/add-ons do I need to achieve this, and will it import as a custom post type?

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