I suggest sticking with OEM GM if at all possible. Unfortunately, good used RS noses are difficult to find. NOS noses are very nice, but you have to be diligent in your search and willing to pay a few bucks or you will miss them. I've been sniped a few times on Ebay for NOS noses. The last NOS nose I picked up cost me $1200, but it's worth it if the car warrants that type of quality.
The repro noses will work fine for driver quality cars, but they are different (brackets, edges, etc.) and will require some extra work to fit decent. They are slightly different in shape, but most people don't notice them once installed.
For one of my last restos, I spent a couple of years trying to get a NOS nose with no luck, so I purchased a repro out of frustration. Actually it took three repros before a decent one arrived. Still not happy with that one, I did a little experiment. Using the upper half of an RS nose from my 72 Z (which got bumped on the bottom) and the lower half of the RS nose from my 70 Z (which rusted out on the top for some reason), I created one good sort of OEM RS nose that is better than the repros. See my pics for some fun. Us car guys will try just about anything sometimes...... Charlie
