The Flight Suit of the Imperial Pilot is not automatically the flight suit worn by today's military.  Comfort is again key while still maintaining screen accuracy.  Some of the best screen captures come from the scene in "Star Wars: Return of the Jedi" when Lord Vader arrives aboard the second Deathstar.  In attendance are several pilots in "off duty" uniform. The detail of this garment shows the difference between the standard military flight suit and coveralls.  Properly altered, the coveralls provide a more comfortable costume.   This graphic from Behrmann & Nathans illustrates the difference from the Military Flight suit to the Race Car Driver costume. However, given the cost of a nomex flame proof race suit, you can modify a "Dickies" coverall suit to mimic this design. Used courtesy of http://www.imperiallounge.com Here is an altered coverall. Note the stand up collar, no zippers visible with pocket flaps and the two shoulder Imperial Emblem Patches. This shows the proper placement of the Imperial Cog shoulder patch and the Comm Pad on the left forearm. Placed on top of the forearm just below the elbow.   Seen here is the covered right shoulder pocket. Real life vendor list for this item: Automotive Workwear  Red Kap Clothes, Uniforms & Coveralls