https://www.homedepot.com/p/Everbilt-2-in-x-96-in-Aluminum-Flat-Bar-with-1-8-in-Thick-802577/204273946
That stuff would work. I don't see any real need to coat it but for aesthetics. Bend, drill, file, sand, etc and use a high gloss paint. Cerakote if you want to get fancy.
Edit: I just picked...