No, an upgraded oil supply line to the turbo is not needed. Ive been told by others that you can float the bearing in the turbo from over oiling. However, i would imagine that to be only the case if you swap out the banjo bolt at the turbo for a different one. The oil flow hole in the stock turbocharger oil supply banjo bolt is only .055". With the stock banjo you really shouldnt be able to over oil the turbo on an upgraded line.
Have you searched on nasioc?
This is what i have come up with for my replacement stock turbo, I did this more or less so i wouldnt have to remove the intake manifold and replace the stock oil supply pipe.