You're not getting a real katana are you?
First, it's gonna be expensive. There's no need for that thing.
Second, it's hella dangerous. Running your fingers down the blade gently with slice them clean off no trouble.
I've been really close to one. A wannabe samurai (who was quite good I gotta admit) came into out school to lecture us and all the rest. He swung the thing round and the tip was within a hairs distance away from my nose
And you'll need INTENSE training. Your physique as well as your technique.
Good luck, though. Just buy a gun, I say.