I'm not sure I'd want to mix in Celtic with Japanese. It just doesn't make a ton of sense.
Graeme is right though. Best to go to an artist who does solid Japanese work and have them design something for you, perhaps based on what you are showing us here, but more appropriate for the style.
if I can,and it wasn't drawn directly me,I always ask for the original art and stencil and I ask them to sign the art,Alycia did for me. :)
I have gotten the art from several artists in the past.
I like to frame them for my office.