Within Windows 2003 there's no PDC and BDC, but DCs one with FSMO PDC.
I've never tested it, but I think it should work: Shutdown your DC, make
an image (I prefer Acronis TrueImage), restore it onto the new hardware
and restart it. There's no additional activity necessary.
While moving an image to new computer, you have to pay attention of
different hardware of course. Graphics-, networkcard and storagesystem
can easily be changed, different HAL is a little bit more difficult, but
Google will help you.