I may be asking the wrong question here but isn't the point of a streetfighter a personal approach? I mean, in the essence its a motor showing, naked and no fairing, minimal approach to other body work, usually solo seat and unusual lighting from what was on the bike?
From there, its all about "you".
I've seen zombipocolypse themes, super hero, military, Asian assassin, hello kitty, obnoxious 80s, glow in the dark paint...the list goes on.
I say start with the body work, and flow with a concept that defines your idea more than an incomplete sentence and "family tradition" mention on a forum.
I may not have a lot to say but it doesn't mean I don't listen.