RE: Which covering?
Solartex does both. It sticks and shrinks with heat. Just don't use a heat gun with it. The heat gun is too hard to control, heatwise. If you heat it too hot, you can't reshrink it later if you get any sags or wrinkles. Use the iron on the temps it says an you'll find it is really easy to work with and looks great - if you are going for a cloth look. If you want a painted hard paint or aluminum look, then go with Monokote or Ultracote.
Check out page 39 and 40 of the Postal Plane Project in the 1/2 A and 1/8 A forum. That plane is covered in red and white solartex.
Tim