Powder coating is a good choice. It lasts for a long time but scratches easily which makes it a pain to touch up. I've used the rustoleom BBQ pit spay paint a few times and it holds up pretty well. Another good choice is high temp engine block or header paint. It can be found in a variety of colors and is good to somewhere around 750* I think.
18.5" OTS, 22.5" OTG, CB Silver(Rip), Vintage Coleman Bullet, Pit Barrel, UDS