Just reuse the stock one, man, I've done that on plenty of turbo cars, you'll get at least one reuse out of it, almost 100% guaranteed.
...and make sure you tighten the turbo flange bolts just a touch before you try to wind them off. That breaks the thread interface and almost eliminates stripping them.
I've even run without one or made my own out of 25 gauge copper sheet. No problems.