If your getting the car with the idea of only doing turbo, then get on eiwhta blown motor because your gonna have to rebuild the motor, and use better parts to handle the boost, unless you want a realy low boost.... I'd guess stock intertnals could hold 5 psi maybe as much as 8, but it would tear up the engine pretty fast unless it's built right. If you wanna do it plan on at least 1,500 for the rebuild and another 1,500 for the turbo. Good luck with it.
1,500 for rebuild is if you pay some one to do it...1,500 for turbo is just for the turbo it's self, and doesn't cover installation.