I know a guy that can fab em up for ya and probably find a set of real skyline tails.
Google Custom imports in Tumwater WA
Leave a message and tell him what your looking for.
He personally but skyline tails on his 240sx with an RB26DETT in it, and basically the whole rear end is off a skyline.
You'll have to call repeatedly and leave messages as his hours aren't set at all.
And do be prepared to wait a while to get whatever you want done.