-- Kristi F
I don't know of any tour groups that visit each island, but that's something you can easily arrange yourself. That's what we did before we moved here. Financially we found the East side of the Big Island to be the most affordable in terms of housing. You may want to look at housing costs to help you determine where to look. A Google search for MLS listings for each island should give you a place to start. Housing sales are a bit slow right now so you could probably get a good deal.
The most jobs are on Oahu, but you can check the job listings for our area in our local paper: Hawaii Tribune-Herald.