You can either do a single file download setup (1 file for the form) and it can show up as a link on the page (via ajax), as an emailed link to the user’s email address (with or without attachment), or both.
Or, you can do multiple file download which is supported by checkboxes. See both the setup instructions AND the screenshots section of the plugin info on here in order to figure out how to set it up as checkboxes — you have to use either an ebd or ebd_left code and you have to get the spacing right (it needs a space before the end / > stuff). See the screenshots.
There is no support for a dropdown.
