If you go the body shop route, they're going to want to repair it. Believe me, this is no biggie. A good, reputable body shop will produce quality results and guarenty their work. You'll never know it was hit and honestly, body putty has come a long way in the past 20 years. You won't have to worry about longevity. It will be fine. Most of it will be banged/pulled out, a bit of putty will be used to straighten it perfectly. This would be the way I'd go.

If you want to go cheap, get a door from a yard. It'll do the trick and you can swap your door trim panel and accessories to the new door from the old one - not a big deal if you know what you're doing. Only problem is - if you go to get it painted, it's going to be expensive to get the entire thing done. If you just get the outer portion done, you'll have a constant reminder that the door was a replacement if you're not able to find the same color door. Finding a replacement door with no dings and the same color is gonna be tough!

Good luck... don't report it to the insurance if the damaging party has offered to pay! Even if it wasn't your fault, it still counts as an "incident". While it won't jack up your rates, you won't qualify for all the "preferred" discounts should you choose to switch insurance companies.