I'd use styrene sheet. Evergreen and Plastruct are the two biggest manufacturers of styrene sheet for hobbyists, and they both make good products. However, you can also use the pre-printed signs available at the hardware store--"Yard Sale", "For Sale", "No Parking", etc. Most of them are made of styrene, and they're cheaper by the square foot, than Evergreen or Plastruct. I bought one, for example, to make bases for a collection of 1/1200 ship models.
As to the awning, I second Obee. I would use real cloth. I save my worn-out dress shirts for just such things. I wear Oxfords, made from a blend (60-40 cotton to synthetic, I think). When the collars fray, they become weekend shirts, and when they wear out at that point, they become raw material for handkerchiefs and for hobby projects. Bleach 'em, then color them as necessary.
Prost!
Brad