Randolphscott,
Just wanted to add my 2cents. I've been on Oahu for almost 7 months and on my second job. I chose Oahu because of the 'opportunities' my family could have here. I have two small boys who I want to have many choices and Oahu will let them.
I also wanted opportunties for jobs. There are plenty of jobs here but they all don't pay so great. If you can secure a job before you get here, then you are half way over here. Finding a place to live might not be so hard. Big Island is probably the least expensive and I really enjoyed the diving there more than Oahu. But, then again, I don't have so many dives at either location. Less than 20 each.
I moved from Japan with a large savings and it has pretty much been eaten up with buying a car, paying rent and various bills. I have a credit score of '0' so you can imagine how hard it was for me to get a condo AND buy a car. Living in Japan for such a long time can make the credit world think you're dead.
To summarize, consider your family, your job and have a backup plan. With my new job, I feel like I'm on vacation now everytime I go to work. Good luck.
Chris