If you're not afraid to do some custom work, one could be built using a cab from the AMT '60 and the rest from from the Revell '65 Stepsside (which has been recently re-released). The Revel kit will provide the chassis, bed, and the front doghouse, the '60 kit has the correct wraparound window and Custom Cab trim. You'll need the stretch the bed and chassis, as both kits are shortbeds. Original '63 kits do pop up, but tend to be rather expensive due to rarity and demand. I don't think that Modelhaus currently has the cab in their catalog.
Here's the parts they do have. That will allow you to get the correct '63 specific parts not available in the other kits.