Lowes carries lots of stainless steel screws. Some of my local
hardware stores also have a god supply (actually avoid Home Depot and
just look in Lowes and if you have a boating place nearby check there
first). I can get small stainless steel nails lots of places. I use
them all the time (I don't used that galvanized crap anywhere, even
indoors). For the bigger nails to purchase locally you might have to
get aluminum ones instead.