Thanks for your suggestion. After doing some careful research on the Internet, I also shorten the list to York & Jurien Bay. It has been quite difficult to contact York via email recently (I am in Vietnam, hence more convenient to ask about the course via email). It seems that there are no one there to reply to my emails. Given that Jurien Bay includes more wind tunnel training (20 mins) and 15 jumps in total to get the A certificate, I might go for Jurien Bay. Just one thing I still consider. 15 jumps for the A certificate is too few.