Hi Clinty,
First and foremost I'd have to say that your family is more important than getting a flying gig. A close second is about how you feel about what you do for a living.
1:Should a newbie be taking this punt at this time of year considering the wet is on its way? (althogh I do have multi IFR and Beaver Amphib)
I think you have bigger concepts to get your head around than the wet season coming up.
2o operators tend to make you wait in line or do they normally hire the best experienced/qualified for the job?
They often hire Johnny on the spot. The old saying "right place right time". They will favour though someone that has all their minimum requirements as it represents an instant dollar turner. They want an easy solution to their problem (lack of bum on seat to operate machine).
3:Should I hunt down a 206/210 and plough off some hours in them? or can i get away without it?
Paying for time in a 206/210 would normally be seen as an unnecessary expense for the average newbie. Basically all they have to do is go up knock on doors and eventually someone will give them a checkride. In your case however it might help. Reason I say this is that you don't have the luxury of driving around for a few years in the hope that someone will give you a gig. You have a limited time frame. I'd say getting to know as many people as possible is probably the key. You could do this footwork get some time in the 200 series and turn up whilst on your LSL to NW WA and go and see Slingair Aligator Broome Av Kakadu Air etc.
Do some searches on this forum and try and get in contact with others that have been in your situation. I think a poster called "The Pharoah" was in a similar predicament - do a search.
What you could do is start informing yourself and making contact with the who's who of the industry. Who has float planes in their fleet? Who employs newbies? What will you get paid (talk to pilots on here about that don't ask that question over the phone - its taboo). Can you afford the mortgage repayments on a GA wage.