Four choices come to mind:

1. Call up GreenTree on Causeway. I know for a fact they have/had a couple wrecked SVT Foci there, you may be able to source 4-wheels from them for dirt cheap.

2. Also shoot Scott (FordMan) a PM. He may be able to help you out.

3. www.fordparts.com is a good spot.

4. You can also find a set of Rota's in your application if you are looking for lighter wheels.