Galvanized Steel or Standard Steel. This will be for the grilling surface.
Bare steel. Galvanized or ANY coated racks will produce deadly chemicals in the food when heated. Galvanizing is a tin coating applied to the surface of the iron. Cadmium is a deadly chemical when ingested and is one of the chemicals on refrigerator racks. I'm not sure about Stainless Steel. The safest way is if in doubt DON'T.
Steel is not good at all for BBQ grills. But Galvanized will kill you. So if you must use Steel. But for the best use cast iron grates to cook on.
most grills have either cast iron or stainless steel grates you can buy them in a variety of sizes at most home centers and from the internet
