No, local powdercoaters can not do them correctly, only a few coaters who specialize in ceramic coating have the ovens that get hot enough to bake it on.
My Son Dan built his headers for his rpu and we found a place in Tampa that said they did headers all the time, so I drove them all the way up there and dropped them off. A week later I drove back and picked them up, and the guy told me something I had never heard before when I bought headers. He told me to run the car at a high idle to bake the coating on. That seemed odd, but they looked fine, so I brought them home.
We installed them and did the breakin procedure like he asked, but after a few days the coating started flaking off in spots. I called him up and he said our headers needed to get to 800 degrees to cook the coating. (I took our infared gun and the headers never got over 400 degrees ) The shop refunded our $ 180 bucks and we are going to send them to a real ceramic coater and have them redone, which is more expensive, but now we see why. Do not confuse a powder coater with a header coating company.
On the other hand, the headers on my 27 came from Sanderson over 20 years ago and the coating still looked presentable when I redid the car a few years ago, but I decided to send them to Sanderson for recoating just so they would look like new again. Not only did Sanderson recoat them, but they didn't charge me a penny and even paid the shipping ! When I told them I couldn't take that for free Nick told me they were happy to do it and to just tell people how good their service is...........so I am.
Don
PS, if you still are going to use your local powder coater to do your headers, have him put it in writing on your receipt that he will refund your money if it comes off........believe me, you are going to need it because it WILL come off.