We do already provide such a wizard. TalendHelpCenter:Installing external modules The remaining items must be downloaded after validating particular conditions and/or create/login to an account on the website of the different providers and can therefore not be installed automatically by us. When possible, a link in in "More information" column helps you to find the starting point url to begin the download.
You can set preferences for Talend Studio to the check for updates of custom libraries on the Nexus server, which will be available in talend subscription solution not open studio.