Be prepared for sticker shock when you buy anything and rent is comparable to the Bay Area. Employment opportunities are scare, but Hawaii also enjoys a low unemployment rate of 4.4%; part of what makes Hawaii difficult is that employers only hire people on-island.
If you're serious about making Kona your home, do your research. Check online for open jobs in your field and find a local address to use in your applications. A car is a must, the Big Island is BIG, roughly the size of Connecticut and Rhode Island combined. Lastly, remember Hawaii-time. Everything moves slower here, but the wait is well worth it.
Employment will be a problem - don't move is you don't already have a job if you need one to survive and pay a mortgage. Don't listen to the realtors that say "No Problem, come to paradise!" They are salesmen that are hungry.
I advise you take a looong vacation (say 2-4 weeks) rent a house for that month and then look for a job - make sure you get a local PO box so that your future employer thinks you live there (Employers hate folks that are "on vacation" and decided to look for a job - so use the rental address and the PO box).
When you find a job you can move - tell your future employer that you live in Hawaii, but have to settle details at home so you'll need a few weeks before you can start - then, go home and liquidate and move.