The ones that come with the stoves are usually porcelain coated. They seem to be durable and provide a non-reactive.
I would expect aftermarket ones to be stainless or aluminum. That being the case, I'd choose SS.
If you can get an porcelain, I'd go with that. The seem to be easier t clean.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan