Stainless steel switches and outlets are not manufactured for safety reasons so the best match would be gray electrical devices.
Kyle Switch Plates carries a large selection of grey light switches, receptacles and dimmers that coordinate well with satin stainless steel switch plates.
Although gray is the most popular, you can also choose from nickel electrical switches however, these are manufactured in a limited number of device options.
For the greatest number of options and best longterm flexibility, Kyle Switch Plates recommends gray devices.