Well just get the dimensions of the USA Flag of where it is suppose to be on the plate.
Then just make up a weather proof Japanese Flag sticker and place it there.
Won't be hard, black outlined rectangle with a red circle in the middle.
Canon 60D = Awesome!
Depends on what type of photo's you want to take.
I just use the standard lens most of the time and have a Telly lens for track days.