If your going to spend 600-800 dollars on a stock turbo, I would definitely replace it with a larger more efficient turbo for about the same money...
Here is a suggestion for an upgrade where you wouldn't need to upgrade any other parts at first if you keep the boost down lower like 10psi... After that if you wanna run more boost, you should upgrade your pump, injectors and perhaps get a AFC to tune with.
http://www.extremepsi.com/store/prod...cat=426&page=1