hi, try "Margaret River Kitesurfing&winsurfing": I got their pamphlet at one of the holiday park's at Yallingup. www.mrkiteandsail.com.au - Simon Peters 0419 959 053. They do "Bunbury to Augusta".
Brenton teaches kitesurfing down in australind. he goes by the name south west kitesurfing i think. if you cant find him let me know and i will give you his number