You can go to a VET supply outlet and buy several sizes of hypo needles, some so small you won't use. These can be cut down with a dremel cutoff wheel, because they are made of stainless steel they will last forever and you can sharpen them with a file. they are of course shaped to a very sharp point and that is why you cut the point off with a dremel tool.
To make screw heads you can buy a cheap (quality) set of mini screwdrivers and cut the tip off and insert into a piece of tube and use that for the screw heads, file the (x) down just a little to flatten it out and allow the tube to also contact the surface.
Good luck