Love my Chef King carbon steel griddle. They make a variety of sizes, so you should be able to find one that fits your burners well.

I bought an antique cast iron griddle like this one from eBay. I like cooking with cast iron & I like restoring old pieces that have been left to languish. Mine has two gatemarks, one on either end, and sits fairly flat on my cooktop. Not perfectly flat, but doesn't rock enough to be a problem. This one pictured has two gatemarks too.

I like the old iron griddle because it's much thinner & lighter than current Lodge offerings. I can remove it easily from a cupboard & carry it to the stove with one hand. It's great for fish, caramelizing a batch of onions, & of course sandwiches & breakfast foods. To clean, just pick it up & take it to the sink for a rinse & scrub. Plus I like the idea of cooking with 100 year old cookware -- someone enjoyed using it in the 1920s, & I'm enjoying using it in the 2020s.

Old cast iron is smoother too, for a more non-stick surface. New Lodge is pretty bumpy. I think the best cookware is vintage cast iron or new carbon steel. I would skip new cast iron except for a few specialty uses, like searing steak.