Yes this website is fab and i have found load of info. I am just at the preparing for the TRA stage but my suggestion for what is worth.
Apply as soon as you can as from what i can see about your jobs you will have no problem getting the top visa which means you can settle anywhere. From what ive seen the visa take between 6 months and 2 years and once you have it you have to set food in Australia within a year (from medical) and then can come back home sort things out and have another 5 years before you move.
I didnt make the move when my children were young and now i have to leave one of them behind as he has a family of his own (although he says he will join us when his OT finishes her teaching degree). Plus best to settle kids in while they are young and make friends easily.
Take the trip if you can manage it and maybe either go on your own or take the eldest and lots of film for the others.
Good luck and hope it all goes well.