Hi Dave
There is some info on requirements for aussies getting married in the Phils at
Living In Cebu Tours - Philippines Marriage Requirements for Australian Citizens and I'm sure i have seen a thread on this topic at the Living in Cebu forum. Try the search function.
We went through this process 22 years ago so I'm sure it has changed somewhat. In those days all the applications for the Certificate of No Impediment were posted on a noticeboard and there was some hilarious reading on the board eg. 70 yr old aussie intending to marry 18yo filipina.
It was imposssible to talk to an aussie official and the joint was staffed with stuck-up filipinas who seeemed to be jealous that they weren't going to aussie too. The waiting time for service was like an aussie hospital. We also had to go to a family planning seminar in Dumaguete before we could get a marriage license.
Not sure if you are intending to bring your wife to oz but 2 guys I know have done that in the past year. One guy breezed through with only 4 visits to the embassy but his wife was similar age and neither had been married before. The other guy has a much younger wife, been divorced twice and is quite aggressive. It took him nearly 6 months to get a visa after he spat the dummy at the embassy staff.
My wife and I lived together in Dumaguete for 2 years before we got married and moved to Perth in 1986. We both knew it was a risk as we were young and broke but it has worked out really well and now we are waiting for our youngest kid to finish high school so we can move back over there.
Best of luck mate.
cheers
lofty