Hi, I am planning to build a drone for geophysical purposes. I need to mount a sensor on the drone. It is a magnetometer and it weighs 2 pounds. I thought I can buy a quadcopter and fix the device on it. I need suggestions on the best model by DJI that can carry this payload. I need the drone to be on air for a considerate amount of time and has a good range of 2 to 5 km. Thanks in advance.