I don't know about the laws in your state. Here they would come up with a value for your van, then add for options. Your 4wd parts- its a good thing you kept the receipts! You probably won't get full value but a good bit I would think.
Then they add up the damage. If the damage exceeds 70% of the total value the van is declared a total loss. If not they repair it, no questions asked.
If its a total you have a choice. Take the money they offer, or keep the van for that total value minus the salvage value. Then you can use the money to make the repairs yourself. Downside is your title is marked as a salvage vehicle.
I went through this with my ranger about 18 months ago. The damage was worse than yours though. The tailgate was about even with the rear wheels! That's when I bought my xterra... it worked out OK. I still miss my ranger though.
Good luck.