Python is just an .msi like any other. You install python like this, using the msi:
msiexec /i python-2.7.6.msi /passive
(use /quiet instead of /passive if you don't want any output at all.... /passive also requires no user input, but still shows the progress bar, which can be nice).
For 3rd party packages... if you can bootstrap distutils into the package (which you can do... check the distutils docs), you can use easy_install. If you point easy_install at a tar.gz file, it will use it instead of trying to download via pypi (though you can allow it to do that too, if you want). This also works if you point it at the exes from the site you mentioned. At least, most of them... there are occasional ones that are different (wxpython, pyreadline are two that I know of).
i.e.
c:\python27\scripts\easy_install.exe my_module.py27-amd64.exe