Robin,
If you are going to spend the kind of $$$ for an awning, then Zip-Dee is the only way to go for an Airstream! You will NOT be disappointed!! I'm a dealer for them, as well as Carefree and A & E, but the Zip-Dee is the best around.
Check out their web site and use the link to the Sunbrella page to look for fabrics. If you like, let me know what you would like to get and I'l get you a 'forum' price.

They are very easy to install if you have the awning rail in place...as you do, and Zip-Dee has all of the size specs on file for just about any Airstream.