It's great to see that you want to do all your research for the interview but I wouldn't worry about not knowing much at the actual interview.
They wont expect you to know everything as there is limited amounts of information that is readily available. Everything just falls under the one banner which is Qantaslink. (sunstate/eastern/impulse etc) As you know the Qantas site isn't very forgiving!!!
They fly Dash 8 aircraft and are phasing out the older Dash 8 -100 series aircraft with brand new Dash 8 - 300 series. Qantas have invested over 100 million on these new regional aircraft and this is one of the reasons why Eastern need to recruit.
Perhaps Sydgirl could help you out :-)
I found the interview really fast...rush in and rush out job for group interviews.