Some autoparts stores sell re-man PCM's with PATS disabled. This allows for the PCM to be replaced at home and the car driven to the shop to have PATS re-programmed.
Or PATS can be disabled with a hand held tuner.
If you go the salvage yard route, try car-part.com.
+1 on matching the make, model, year, engine, transmission, anti-lock brakes.
2003 GT Convertible (sold & missed)
2000 GT coupe (Craigslist project. Fixed. Now my DD). Windsor to Romeo swap.