Hi Kaznost :D
Boy so many questions!
I'll try my best to help here..its been a few years ago since I did the big move mind you!
There been a post here that maybe of some interest about the costs etc
http://www.pomsinoz.com/forum/viewtopic.php?t=11
The website to visit would be
www.immi.gov.au to get you started but be warned it can take over a year. I think this have speeded up now but not sure.
As for immigration it works on a points system and you get points for age, qualification, experience etc. I would think that either one of you should be able to get in and if engaged will be treated as just the same as married. Again have a look at the paperwork on the immigration website.
You qualifications get assessed by the relevant body and they let you know how many points you can get.
I can easily say that moving here was the best decision ever. House prices are going up considerable over the last few years but it is still more affordable that it was before.!
Hope this helps
Anymore Q's just posthere and I'll be happy to help.
D