Weinstein5 - As I understand your response, I cannot run one box with esxiv (with 2 virtualizations), and have the XP virtualization talk to Windows Server virtualization.
You propose the box run a modern Windows OS, then virtualize both the XP and WS2003 on it. The XP can then talk to WS2003 on a virtual network.
Did I understand you correctly?
I do not have any Linux experience, so I would prefer to run a Windows host than Linux.