not that im #1 by any means when it comes to nitrostyrene chem, but what what ive read i believe that nickel sulfate could be substituted in a urushibura type reduction. as long as its soluble, yes. you will also require more of the sulfate salt of course because NiSO4 is only about 1/3 its weight in nickel wheras NiCl2 is about 1/2. NiCl2 shouldnt really bee a problem to obtain for you, just visit an electroplating store, NiCl2 is avaliable in crystaline form or in solution.
i believe the nitroproPANE the writer is referring to is the same chemical as your nitroproPENE, it can be reduced in the same fashion the writer describes.
nitropropenes will polymerise after a few weeks of standing, you can extend their life by storing in the freezer.