Over the door suggestion
Keeping the same crop ratio of the image, I would suggest a 16"x 30" aluminum display with a satin finish. The Satin finish is something I would special order. This will prevent the reflection from a high gloss finish that you would undoubtedly get with a glossy finish.
I also add rounded corners just as a safety precaution. The back will have an aluminum frame and wire hanger making it easy to install as shown in this gallery.
This image is an approximate sizing.