Microsoft® Windows® Software Development Kit (SDK) for Windows Server code name “Longhorn” and .NET Framework 3.5

I have been able to find this link on microsoft.com http://www.microsoft.com/en-us/download/details.aspx?id=32393 but the installer that gets downloaded is not for 6.0a as the documentation claims it will.  I would like to find the iso with 6.0a on it so I can burn it and get this sdk installed on a development machine.  I am specifically looking for 6.0a not 6.0 or 6.1.