Ad Astral was great, did mine there 12 months ago. From memory, paid $500 up front then about $3000 every few weeks to cover the progressive costs. THere's nothing dodgy or fishy about them at all!
The training is top notch too although RM can be prickly in the air during the flight test.
The only downside was the Dutchies needing maintenance and the airport being so busy meaning some delays getting back into PPH after airwork at RTI. Also, Perth is bloody expensive these days if you havent got family or friends there so consider that in your costs. I had to hire a car for 5 weeks plus living costs. It all adds up.
Definately the way to go tho