Migz,
As Radimus pointed SYSPREP is king for this in 2000, on Nt you have to take a more complex approach.
We do this by taking a ghost image of the NT machine just before the disk is converted to NTFS, then we have a bootable floppy which runs a REXX script to ask the user a bunch of quesions, ghost the FAT disk image onto his drive, and then customise some answer files, then take the floppy disk out, reboot and NT continues the install unattended - you then need a series of auto installing apps (office etc) built using ZAK or the like.

We used to use it before 2000 hit the streets - it took a while to set up, but it meant that rebuilding a PC took about 90 minutes, with 15 minutes of interaction at the start (mostly waiting for the image to ghost down).

Id go 2000 and SYSPREP if you have the choice.

HTH
Mark