Definitely better off replacing the front wings at least you'll know they won't have to be touched again. for the rest probably cut out the offending area depending on how bad they are and weld in new bits.

I had a similar job done to my e34 a couple years ago. I got two new front wings, front and rear bumper sprayed, rear arches, rear sills and jacking points welded and sprayed. My car is black so I didn't get the whole car sprayed as its easier to match a darker colour and he got it spot on. It cost me 1100 not including the price of the wings. But I paid cash and I knew the fella, so you might have to double that price.

Sent from my SM-G960F using Tapatalk