Decison, decision, hard decision!Need help

Last month, I have attended two interviews and got two offers from both companies. One is in Perth, Australia which is quite far from Canberra where my family is now. The other is local. Both offer the same package, but they were giving out in different time. The problem is the Perth company gave me the offer after the interview directly. After one week late, I received the formal package. This job is through a recruitment agency. I had the confidence that I will get the offer from the local company too. But my wife, the recruiter and the company kept pushing me to accept the offer. After having waited for the offer from the local for almost one month without anything, I told the Perth people I will accept the offer and will start to work in May. This week, I receive an email and several calls from the local company about the offer. I talked this with my wife. First she is quite supporting me to be an honest and royalty person. But after talking with her colleagues, she turned herself back. With the local company, I do see a lot of advantages, especially for the family. We have a 10 months old girl and we just bought a house and land package in Canberra. With the Perth company, I do see a lot of development potentials too.

The local offer is with a small company, with only several staffs. But they are doing a lot of consultant projects around the world. Some of the projects are defence related. The chief engineer is a PhD. I have met other staffs except the manager, the chief engineer, and the HR manager.
The Perth company is medium size company, with about 50 staffs. Among them, about 40 are engineers with 40% of the engineers are PhD. I have met a lot of people in the company on the day of interview. I can feel the chemical there is just right for me.

If you were me, what you will do? If I would accept the local offer, how can I speak to the Perth people?

Thanks in advance for any help.