Go with the 182. Much better cabin space, range as well as takeoff and climb performance.
Operating costs annualized will be in the same relative magnitude on both airplanes. 182 burns about 40% more fuel and is about 20% faster than 172. All other costs (insurance, hangar, maintenance etc) will be in the same ballpark for both a/c.
Your capital outlay is obviously greater on a 182 but both types have good residual value.
As for bringing one from the US, that generally makes most sense on later model aircraft due to the cost of ferry flight and "propina" for your friendly local Customs folks
