For what it's worth, I think most fair size towns are going to have a fastener supplier of some sort around, and they are a good place to have a look. Often better than the local hardware with it's endless rows of little plastic trays full of mixed up fasteners which have been graciously rearranged by previous customers!
In my town, there are a handful: Fastenal, Granger and some other agricultural/industrial suppliers. The downside is that package sizes are often large, and for some fasteners I could only get packs of 50 SS allen head bolts. However, some times is pays to get to know the lads behind the counter, as after seeing me come in looking for a motley selection of bots so many times, the store manager got to know I was working on old bikes, and gave me a better solution. He said to make a list of the size/length/type of bolts/fasteners I needed, and how many, and he would order in exactly what I wanted. Essentially making my own customized kit.
All that said, I have a Z1Enterprises bolt kit on my 650, and it came with everything I needed to replace my fittings with SS, and a few extra as well. (Maybe other models have a few more case screws/accesories somewhere? All that said, you've got lots of options. The bolt depot also looks pretty good from the quick browse I had.
Cheers,
Jon