I am looking for options for an organization that have multiple agents across a city that has an area of of 35 square kilometers. Most of the employees will be in the field and we are looking at means to make communication easier. I was looking at the Motorola MR350R as its said that it has a range of 35 miles. So in a real life scenario with all trees and buildings I am assuming it will be broken down to 5 miles? Any other heavy duty option would you recommend?