Hey Mate, If you are looking for bladders have you tried:

http://www.slingshotkiteboarding1.ashop.com.au/c/119186/1/le-blanks.html

They are leading edge bladder blanks so you just let them know what length and they will send out a standard bladder. need a valve or two as well but can get the whole lot for under $100 (depending on size). They also do struts aswell.

The benefit of using these blanks is that they never fully inflate to size so most of the pressure gets put on the kite material.

Just thought it might help if youre having trouble getting bladders.

Cheers, Luke.