Pretty much hafta make your own. There are so many variables, they're really hard to find pre-made stuff, unless you might go with standard sizes, then you could have some local metal fabricator make it for you, then powder coat. I don't get the eye hooks at the top.
Anyway, there are a myriad of ways to achieve that effect..... some easy, some difficult. However, I would never make an exposed wooden frame for a metal sign. Looks dumb.