I use the standard gold or silver plate fish-hook style on most of my ready-made earrings but can change them to surgical steel at no extra cost.
Many of my ready-made designs can be changed from the standard fish-hook ear-wire to a stud, lever-back or one of the non-pierced styles and all of my custom designs can be ordered with any style and material. There is a price difference for the decorative styles of ear-wire or for other materials including Niobium, Sterling Silver, Gold-filled or Vermeil.
This picture shows the difference in shape between the standard fish-hook and the more decorative style and also the colour difference between the Sterling Silver-plate and the Surgical steel. It also shows the other popular styles of ear wires I have available.