Adfast is the australian importer so any bike shop that has an account with adfast should be able to order them in for you, having said that I belive that they are out of stock atm (I get my shop to do a standing order for me in advance). I did look into importing some from the usa at one stage but the freight charges were prohibitive (it made them almost twice the price). Another thing to consider is that when I imported some tyres from China I got hit with an aditional qurantine fee because they are an organic product so had to go through quarintine. The guy I contacted in the usa was advertising them through ebay usa he is based in texas, sorry I dont have his contact details anymore.
Saber