TIE/AT-AT helmets you don't really have to wait for. Get a Stormtrooper and a Luke/X-Wing and make a new mowhawk strip from sheet plastic. Most of the greeblies are on shapeways. About the only thing I'm not sure of are the earcaps. Still leaves the life-support box -- but Inferno Squad would be no trouble at all -- the helmets are discrete unto themselves.
The only issue there is the mohawk is 2 inches on the rebel helmet. The ties are 3 inch.