You do not need:
. a server with an "administrative installation point"
. an "Enterprise" code
. a "third-party" tool
The Microsoft deployment tools for XP have all you need. I do agree with DallsKelsey on one issue, that is that you should look to the msfn.org site for assistance:
You can use the deployment tools to enter multiple license keys and create an unattended answer file for product CD-keys, you can even depending on license encrypt the keys:
Service Pack 1 adds an encryption feature to unattended setups of Windows XP. This feature is applicable to customers with volume licensing agreements with Microsoft such as Microsoft Select, Microsoft Enterprise Agreement, and Microsoft Open License. Customers who place a VLK in an unattended setup file (unattend.txt) will be able to encrypt the VLK such that it will be time-limited (in increments of 5–60 days) and not visible as plain text. This feature provides customers deploying Windows XP with an additional layer of protection by obscuring the VLKs in unattended installations.
How to Use VLK Encryption
Scenario 1
To protect for 30 days SMS-based, RIS-based, or network file share-based installs using the volume licensing version of Windows XP:
From the command prompt, run:
winnt32/encrypt:"XXXXX-XXXXX-XXXXX-XXXXX-XXXXX:30"/unattend

ath_to_destination_unattend_file[/Q]
The resultant hash value is written to the specified unattend file, overwriting any existing ProductKey or ProductID entries.
A message box displays whether the process succeeds or fails due to an error.
If the /Q switch is used, information about the success or failure is written to the file %Windir%\Winnt32.log
The product key entry in the unattend.txt file is functional for 30 days after the date of encryption.
A script to re-encrypt the key regularly could be created to ensure that a new encrypted key is always available for the install. The Task Scheduler could also be used to schedule this task to be repeated automatically.
Scenario 2
To protect for five days a CD-based install using the volume licensing version of Windows XP:
From the command prompt, run:
winnt32/encrypt:"XXXXX-XXXXX-XXXXX-XXXXX-XXXXX:5"/unattend

ath_to_destination_unattend_file[/Q]
The resultant hash value is written to the specified unattend file, overwriting any existing ProductKey or ProductID entries.
A message box displays whether the process succeeds or fails due to an error.
If the /Q switch is used, information about the success or failure is written to the file %Windir%\Winnt32.log.
The product key entry in the unattend.txt file is functional for five days after the date of encryption.
The unattend file could then be placed on a floppy disk or burned to a custom CD image to provide a short-lived CD for CD-based installations.
And Daniel Petri's notes: