New SPS content live on TechNet
Automated Installation of SharePoint Portal Server 2003 : https://www.microsoft.com/technet/prodtechnol/office/sps2003/deploy/autoinst.mspx
Using SharePoint Portal Server 2003 with SharePoint Portal Server 2001: https://www.microsoft.com/technet/prodtechnol/office/sps2003/maintain/coex-sps.mspx