iam making controls for the xbox 360 as well. each button has a seperate ground, you can t daisy chain- iv tried and it dosnt work. so i you have bought a sanwa JLF with the pcb your screwed. i had to go and buy a semitsu LS 32- wich i am so gald i did as its easy to wire up and performs better in my opianan.
so what iam saying is your need two wire for each button (one for common and the other for ground)
also if u want to do the triggers- its very hard work.
hope that kinda helps