if you are talking about the hex key screws in a variety of
colours, those that need allen key to open, you can get them at
Regina's on the same block as Ah Boy. Most other motor tiams also
have, hou just gotta ask them, but they'll kill you on the price,
like $1 for each screw.
better yet, if you want to buy in mass, there is a shop at UBI ind
park that sells nothing but screws, you can try there.