Poke around on this forum, it has been reported that there is a way to accelerate part delivery from Isuzu that involves the dealer telling Isuzu your VIN. Something about Isuzu wanting to discourage dealers from stockpiling but if they have a VIN then they believe it is for a real customer and will ship pronto.

Also, why are you getting new headlights? Depending on their condition, I might be interested in buying your old ones to use for designing a custom HID replacement.