the movie operation scorpio has lau doing a good display of it.
I don't know fu too well but I think that might be a good representation of this.
I think that it is also called the scorpion king and lau is REALLY good, so it is probably mostly movie stuff but his form looks as real and authentic as it gets.
I seriously think that this will help clear up some of these questions, because the no shadow kick that he desribes is one that you can't see coming, sure it leaves no shadow because it is fast, but where the no shadow comes into play is balance, where you can't tell which leg he is going to kick with. Kind of a dumb movie but good action, funny, and a disciple of wong fei-hung himself. He ws not a direct pupil but I believe his masters master was wong, just guessing though.