I modded my Traeger Texas Elite to hold another grate above the factory one. It looks like I'll need one that measures ~35" by 15". I called the local Lowe's, but no luck there. Any online sources? Thanks.
You can get it at the Hardware store. Looks like this.
You can cut through it pretty easy as you can see to a custom size. It's easily reinforced with some steel rods as well. No welding required, you can thread nuts and bolts through it and get all sorts of Erector Set with it. Or weld it on if you have the skills. Lots of custom rigs use expanded steel grates.