I don't see there being anything technically wrong with it, but the majority of the forum prefers original or obscure portraits, or famous actors not involved in Star Wars in any way. Mass Effect, Star Trek, and other popular Sci-Fi works generally receive eyerolls; I myself just changed one of my characters from a Mass Effect Cerberus trooper to something more obscure after... uh... "feedback." Ripping off Star Wars stuff that used to be canon but isn't is probably going to be contentious even if permitted.
EDIT: Now if you're using obscure Star Wars characters, or background actors, who happen to be wearing the right uniform and have a clear enough shot but no one knows who they are, like random Y-Wing Fighter pilot XXX-427 or Stormtrooper GX-6666 (or someone like Admiral Statura) then you're fine by me. Picking up Darth Revan because he's no longer canon is a load of BS. Using Darth Talon might be acceptable because she's the only red skinned Twi'lek I can think of, but really there's tons of people-created content for that too.
Used obi wan...some people joked....they got over it.