Nice project. I presume it's the frame you intend to get powder coated. Have you thought about painting it instead?
I know powder coating is a durable finish and is popular for motorcycle frames these days, but I've never understood why. It has several disadvantages. It can crack and chip off. It's impossible to touch up if you have to repair or modify the frame after coating. Some powder coaters are better than others and the finish can be unreliable (I've seen some truly awful PC work with bubbles and pinholes in it). It's difficult to remove if you need to (for electrical earthing etc.).
I much prefer a nice coat of epoxy paint. It's just as durable as PC and doesn't have the disadvantages mentioned above. And the big bonus for home restorers is that you can do it yourself without too much investment in equipment (once the frame has been sand blasted).
Good luck with the project,