if this were my job no doubt I would:
1- 1x2 aluminum framing with .063 or .080 aluminum faces 5x12 sheets AND i would try and talk them down to a 12 x12 circle to make it easier.
2-another option is to order white lexan for the face. it can be cut to 14' that would make it easier, a little uncalled for I admit
3- flex face with digital print and stretched over a frame