Are there no athletes on T-Nation? Someone has to know this.
I am no athlete, but my understanding of the matter is that it is not only about strength in your lower body, but also about flexibility (Kadour Ziani says it is why he has a world record vertical) and not carrying around a lot of fat (One of the contributors on here said that he noticed a correlation between those who could do the most pullups and those who had the lowest 40 times and best verticals).
I have seen people use these shoes that are like platforms for your toes that are supposed to increase your vertical too. They have their own program though to go with them. My cousin used them and he said they worked. I cant remember what they are called though. Sorry.
I have no clue what WS4SB can do as I am not familiar with that program, but I don think that scrapping squats (the primary developer of lower body strength in SS) is a fantastic idea.
Seriously thoug Kadour Ziani is a beast. He is in slam nation. Check him out on youtube.