Welcome to the forum and to the crazy world of reproduction flight jackets.
US Wings and US Authentic do not make true reproductions of World War II A-2s. They make their own jackets from their own patterns "inspired" by vintage A-2s. Ergo, the materials and fit will be different from original jackets, as will be how the jackets look. For the price point, they are not bad options, though you might also want to look at the Gibson and Barnes historical A-2s as their quality is very good. (Gibson and Barnes also have their own patterns etc., though, so they are not true "reproductions," either.)
http://www.flightsuits.com/index.php?id=18&cat_id=18
If you want a true "reproduction" A-2 that is based on an original model, your options are Good Wear Leather in the U.S., Eastman Leather Clothing in the U.K., Aero Leather, also in the U.K., the Real McCoy's in New Zealand, or one of the Japanese makers (generally more expensive and harder to find... these include Buzz Rickson's, the Few, and Toys McCoy, among others).
For a good introduction to this subject, look at the Acme Depot web site. It is a bit out of date, but still full of good information and reviews.
http://www.acmedepot.com/a2jacket/a2repro.html
If you spend enough time here you will pick up lots of good info. Poke around as much as you can and don't be afraid to ask questions.
Cheers,
Matt