I really cannot see shit from the pic. I would need a close up of what the two ends are. I believe you are correct in saying it is a stainless line
Is it a stock turbo? If so, there should be a banjo fitting on one end of the line (---O). The other end should have another (if you plan on taking oil off the head) or you would need a fitting to get it off the oil filter housing. If the other end of the line is not also a banjo fitting, the thread for the oil filter housing is inverse flare thread. Not a "common" hardware store size. You would need to bring the line in with you to get a fitting that will match the oil filter housing and the line which is usually 1/4 flare.
If you plan on taking oil from the filter housing, try and remove the plug before you go through the hassle of looking for a fitting. They are on there tight. I stripped the fucker on my old motor (the plug). I ended up getting a 1/4 flare elbow, and tapping the one side to metric bolt thread (possibly 8 or 10mm. Just check the banjo bolt for thread size).
Hope that helps at all. If you can get a better pic of the ends, I may be able to help you better. Just throwing out ideas above.
Threaded Mode