Hi Richard Last year I had a similar problem but with trying to find copper nails. I surfed around using the search word of 'COPPER NAILS" and found a web site that dealt only with fasteners, including a hugh line of nails....where I was able to find what I needed.....sorry, but I didn't keep the web site address....but its out there :-)
A word on aluminum nails: I have replaced them up on my ridge vent on aluminum gutters (spikes). Reason: they don't hold. The aluminum seems to be a slippery metal that doesn't 'bite' like galv steel, and will work its way out over time. Since I have replace the aluminum with galv screws (ridge vent) or galv spikes (gutter), I have not had a pull-out problem. There are some that say this will create an 'electrolysis' problem, but after 2 years, I haven't seen any problems.