IRRC, 78F350 did a great job replacing the exact same panel and posted pics. I'm not saying it's a DIY job by any means, but if you're curious as to what's all involved you may want to look for his thread.
Regarding the insurance? You can let them total it and buy it back off them. But then it'll always have the "reconstructed" title once you repair it. Until then it'll be a salvage title and you cannot drive it.
You may ask if they're willing to pay you up to just below their "total" threshold, if that's even possible. But if you can manage that, then you'll still have a clean-titled car, and by the looks of the damage, you can still drive it around until you decide to repair it on your own dime.
I feel for you, man.
EDIT: I found his post:
This & That
Threaded Mode
