Cameron, we never have hail here that I've seen, but my orchids are protected from heavy rain, birds and critters, and flying tree pieces etc. by our pool cage. It is made of window screening, and you can get screening material at HD or Lowe's in a roll for very little money. How about a PVC frame with some window screening attached to it for an awning over your orchids? It reduces the sun's intensity by about 20% but my orchids seem to like that amount of light very well.
Screening material is made of fiberglass or plastic fibers, but you can also get metal screening material - even hardware cloth 1/4in. holes, metal screening - would surely protect the orchids from large hail, but wouldn't impede the light getting to them very much. Again, a simple frame made of PVC would hold it up just fine. Paint the PVC though because it doesn't stand up well to sunlight.