I'm applying for a 189 visa.
you could look out for seminars going off such as "down under live" or "Thames migration" they have RMA's and other companies there to give advise and rough costing's, and they will look at the points system. They also usually have reps from SA and WA to give you info of areas. They cost £10 to attend but well worth it. We went to both of the above and employed a RMA from attending these. Not had any issues or bad advise and everything so far has gone smoothly. We hope to get our visa Dec this year, we started the process January.
As for the IELTS the key is to practice as much as you can. Also you can have pay per hour Skype sessions with IELTS examiners. If you are really struggling I'd recommend this as they tell you exactly how to approach the tests. They also send you out other tests practice papers. The online 30 hours free tuition provided when you pay have very limited resources and you get to remember the answers. I took 3 tests in total but one I appealed and that came back positive, so didn't really need to take the third. If you do go for the IELTS I'd go for a venue that doesn't have lots of applicants, some can hold over 200 people!!!! If you want any more info PM me.
If you go for 457 depending what area you are wanting to work in you may still have to take the IELTS. I know a cardio surgeon that was on the same test as me had to get 7's in his IELTS even though he had a job out there on a 457. As far as I am aware all Health/medical related work you have to have the IELTS.