88 SR5 fender replacements

I have an 88 SR5, and I want to do some stuff with it if I can only get rid of 4 rust spots. I've sanded them out and plan on going to a bodyshop for a paintjob.
Before I do this, I wondered if anyone knew if you could get just the fender pieces replaced. I was told that GM does this by cutting out the rust and welding a new piece in its place.
If this is not possible, does anyone know what cost im looking at to replace the entire panels that have rust on them?

just go to some local wreckers and look to see if they have an sr5. you'll probably be able to find the parts you need for cheap, and it doesn't matter if they aren't your cars colour because you're painting it anyways. it'll probably cost about 1/4 if not less the price of getting it from a dealer