Boy I tell ya, that car is one of those deals where the engine will outlast the body several times over. So finding a good body with a bad engine may provide difficult.
The last A3 Jetta I had in here was a rusted wreck, 1/4 million mile gasser. The old ABA ran fine though.
I liked my '98 Jetta a lot when I had it, but the newer cars are really superior. And parts are more available for them too.
But maybe you can find a really low mileage pampered car from a non-salt use area, who knows. Most of the diesels got miled up pretty quickly.
Good luck with your search. If you decide to sell your wrecked car, post it here. Lots of good transplant opportunities for the AHU... like a diesel Vanagon (hint hint).