Having a gas fireplace insert doesn't mean you have to sacrifice the realistic look of logs or coal. Find your right gas burner for fireplace inserts here at eFireplaceStore. And with our low prices, it's never been easier to upgrade your burner for fireplace insert.
Is there a faux coal burner available that is designed to use L/P gas? We have fully functional crock flue lined fireplace chimneys and also have period cast iron coal baskets. Basket Inside diameters are 15" at front 9-1/2" deep and 13" at the back.
Based on your dimensions and description, I believe this Coal Burner will work just fine for you.