To add an entry to the Project Types dialog box, you need to install the project template (zip file containing the .vstemplate file) as part of your installation. You will want to do this from your installation, not from VSPackage itself.
However, your .vstemplate may call a wizard written in C #. Although this is truly a "custom wizard", you can provide a link to the .NET assembly. No need to use scripting language.
. IronPython > # Example.IronPythonProject SDK VS2008. , , , , -.