Take a bunch of pictures and your bike to a good exhaust shop and see what they can do.
That I know of, there is no bolt on header set that looks like the 400.
Maybe not an exact likeness but similar to it. The exhaust shop sounds like a good idea but better have your checkbook ready unless they take cash though.
Of course, no matter which way you go, you're gonna need some bucks.
Lots of luck on what ever you end up doing.
Later on, Bill