This is an old thread and you've likely since solved this or moved on, but I wanted to at least suggest a few things just in case it is helpful later..
The Package Manager is responsible for deploying packages to Hosts. A package will not be available in that list unless it is also available to the Package Manager to deploy. The steps in documentation refer to this requirements in Installing Packages on a Host. To download packages to a Package Manager that can be later deployed to hosts, please refer to Downloading Packages to a Package Manager.