What you got off me are the stock R34 side skirts, the one you have in that pic is a Nismo option and they are f/g pretty sure and very hard to find. The only other you may find are the dealer fitted Altaza (or however you say it) skirts that are full length, these are hard to find also.
The blue car has the Nismo kit and the silver one has the dealer option kit (my old R34)
It took me a long time to get hold of the dealer kit, that's why I had all the stock parts that you got off me