If you can't get new ones, repair them. These are the steps I used on the left front fender:
1. Remove it. (Probably going to break off some bolts if it was as rusted as mine.)
2. Brush out all the junk, rust and dirt (and in my case a big friggen black widow spider that got really pissed off.)
3. Knock down as much of the rusted area as possible with a grinder.
4. Treat affected area with rust converter/metal prep and sand as needed.
5. Fill and rebond with long strand fiber glass structural filler.
6. Gind/sand to rough shape.
7. Fill with "bondo", formula 27 or other product of the type and sand to shape.
8. Finish and fill imperfections with glazing putty.
9. Completely sand with 80 then 100.
10. Spray with primer sealer and sand as needed.
11. Spray with primer and sand as needed.
12. Paint.

(Note: Use all fillers thinly as possible for less chance of cracking and breakage.)

Quite a process but it is worth is. My fender was literatly falling apart. The back of it was almost all the way rusted off near the door. I mean you should have gotten a tetanus shot just too look at the thing. Following the steps above gave me what looks like a new fender that I just put back on the car today.