If you are mostly at bases in the US, you can use the post office web site http://zip4.usps.com/zip4/citytown.jsp to find zip codes in your next city.

Use the AMA club locator http://www.modelaircraft.org/clubsearch.aspx to find clubs in the area. Most have a contact phone number. I recommend using it rather than trying to make contact via email. Explain your situation and see if an instructor might have a trainer you can use while you are in the area. I'm pretty sure a few guys in our club would do this, and we would not expect you to join the club if you were only going to be in the area for a short time.

You'll probably need to join the AMA to be able to make it work, but $58 per year is a bargain to get great help.