I have the Kawi Kit ECU on my zx6rr. Before i purchased it i did alot of research on it, alot. If you have any questions ask me, im sure i can answer them for you. Its an awesome product and an even better platform to start your mods from!
You dont need to, but if you want to program the Kit ECU you can either buy the Kawi Cable ($400+) or the pc III. You can get the same results and most programers are more firmiliar with the pcIII over the Kit ECU.
No the Kit Ecu is a direct replacement for your stock ECU. The default map is on the Kit ECU is good for 10hp on the 6rr and 6 on the 6r.
Now lets say you want to get a custom map on your Kit ECU (just as you could do with the stock ecu) you can either map through the pcIII or the Kawi Cord . With the pcIII its easier to map cause most mappers are more firmilar with the pcIII than the Kit ECU. Plus the Kawi Cord cost more than the pcIII.