You could send letters to the businesses you are interested in working at and include the fact that you are moving in five months. It would be best to not mention the fact that you don't know which of the three towns you are going to move to. Instead write each letter like you have made the decision for that particular area.

This is a very iffy way of deciding upon your new home, though. I am thinking that it would be better, and less expensive, to do your research online. Access Careerbuilders, Craigslist, Monster and any other job site you can think of and input the towns you wish to move to. Figure out which town has the most or best opportuities.

Check out the towns websites for unemployment rates and other statistics such as crime rate, best schools (if that is a concern for you), housing market, cost of living margins, etc.

Employers may have a need for someone with your skills in the field you are pursuing right now, but in five months they won't have that need. It goes the other way as well. Right now there may be absolutely, or limited, need for work in your industry and then in five months, there may be a lot.