Hi Shiroe,
Hmm Samurai armor, not really - I don't have any models for it. Unless it could be made from different parts of existing armors or costumes in the game. I recall a couple of plate armor parts that remind me a bit of Samurai armor but I can't think which ones it was off the top of my head. You could use the reforge system to use those on your armor.
As for weapons, the only ones currently in game that look a bit like Samurai swords are maybe the Curved Blades schematics for Dual Swords, but there is nothing really for Greatswords. I will add some more weapon schematics soon so I will keep an eye open for Katana models.