My boy's fussy too - he loves Satin Balls and they do put the weight on. There's some recipes in the second post here: http://www.dolforums.com.au/index.php?showtopic=81686.
Pookinuk will deliver it to Perth for $5 per delivery. They're also pretty quick at getting back to you if they're out of stock or you want to ask a question.
http://www.pookinuk.com.au/pet-products.asp?categoryID=90