I am not sure on this turbo specifically, but I do know that Turbos can be rebuilt. The only thing I think that would stop you from bolting on a new aftermarket turbo is the connections to the factory plumbing. In which case, a nice weld shop can fab this up for you.

I would not go for the newer turbos if I were you. The engine management is not programmed for more boost. You would have to look at a stand alone controller, or get some shop to do this for you, maybe they can reprogram the factory one, but this would change your price drastically.

It would be nice if someone could find the specs for the factory one. Finding a replacement would be simpler.