When the '04s were "new" there was a company that had the parts in a kit to turn an 02-03 front end into an 04...(cant find it now)
In my best guess the major parts you'd need from an '02:
-Bumper cap & beam
-L & R Front fenders
-Hood with old scoop
-Grill & side peices
-skid plates & possibly inner wheel well plastic
-lots of little hardware
-a lot of tinkering/customizing incase they changed wiring & core support for headlight mounting...
Your best bet is to meet up with an '02-'03 owner & take there headlights & grill out & compare...