apalsson

You are probably better off to get them from original sources as some who do resell them in Oz are just price gouging especially for Dawes valves. There is a number of opportunistic swines currently doing gouging/fleecing unsuspecting customers and even going that far that tacking Dawes on their Diesel chips kits as some miracle cure boost fix engine safety. Diesel Smart, Roo systems among a few, they just ripped off the whole "know how" and claiming it as their own with the price tag to match. Supplying of the shelf Diesel chip with heatshrink covered Dawes valve, some harness and EGT gauge they get from US for peanuts and charge you a fortune for the privilege, you bet it is the best thing since sliced bread/cheese whatever.
 

As for Dual Dawes without solenoid nope you can't, I thoroughly recommend going Dual Dawes with the solenoid and needle valve and Jaycar voltage switch to control the whole setup especially on 05 Di.

I've done it in stages, first Dawes only, than added needle valve and than dual Dawes with just manual switch and just recently voltage switch to automate the control but I also retained manual overide so I can decide when to have low or high boost only or both automatically controlled via throttle switch.

I wish I had done the whole shebang right away.

Cheers