Craig, I think Behr & Nissin are equivalent in kwality.
I'd use either.
About the hit, well, welcome to the W124 world. These cars scrape up there quite easily. You need to be VERY careful entering & exiting any parking lots or streets that have a dip. Better yet, go across them at a 45 degree angle. This particulary applies if you have lowered your car at all (like mine).
You should have the car straightened out by a body shop. If you don't, you risk having the space between the fan & radiator too close, and you can have the fan chew a hole in the radiator tubes under hard braking. A friend of mine went through 2 radiators before he figure out the real cause! A trip to the body shop (and a 3rd radiator) cure it.
Good luck! :p