Living among panamanians (Panama City)

Hi,
About to move to Panama with my family, for about a year with a fairly-paid UN-contract. We are looking for a house with three bedrooms and a garden. So far, all options point to the same zones of the city, which look too up-scale and too expat (sorry, no offense intended) for our taste. In order to take advantatge of the opportunity of living in Panama, we would like to live in a middle-class zone where regular local families live--not among the elites. Problem is, whe don't know where to look at. Any recommendations about safe, down-to-earth, not-too-crowded barrios?

Thanks!