A pretty rare costume that makes you the star of each Star Wars event.
Imperial Death Star Gunner
Most easy to buy a black overall and sew some imperial logos to the shoulders. You may get the leather-part sewed at a sewer but I used the same one as for my Tie-Pilot. The belt is the same used for a Tie-Pilot or Officer-Costume.
Who doesn't know how to work with fiberglass, shall search for an Altmanns-armour-helmet. This is extremely rare and expensive. For my taste The Altmanns Helmet is a bit to small but still the best on market. You may apply some tinting-foil from Cars for the visor to make it a bit darker. I also recommend to apply som foam inside to make the helmet more comfortable to wear. It is very important to wear a black mask underneath the helmet, otherwise your neck will be visible.
This is rather simple and cheap. You most likely want to get a pair of black military boots. These can also be used for other costumes like Officer, X-Wing-Pilot or Tie-Pilot
I bought some cheap black gloves and got them enhanced by 20 cm at the underarm-area with black leather. Really a cheap solution.