As for Gintama Sougo Okita cosplay, all we need are the light brown hair, black Shinsengumi uniform and the red sleep mask with eye markings, and the Katana and large bazooka are his weapons. Sougo has round face and red eyes.
It looks like that any cosplay boys and girls would be quite cool as long as they put on the standard Shinsengumi uniform, together with the sword or bazooka. Why not give this Gintama cosplay a try?