AD in W2K is strictly a top affair that needs to be well thought out. I would advise against letting someone deploy their own prior to the proper Forest ROOT being established by corporate. Windows 2003 is suppose to have prune and graft capabilities (which I have not see) but I have not yet read you can change the Forest Root.
Definately need to run that past M$ to see if they will be providing you a method of having such a domain become a child of your new Forest.
