I work for a local search and rescue organization, none of whom have any experience with drones. I am contemplating building a drone large enough to carry a camera, but also a small payload to drop off first aid or other supplies to those lost or stranded until a team can get to them. I am contemplating a 5lb payload or roughly 2500 grams in addition to the weight of the quad/hex or octocopter, so a minimum thrust of 2 times the payload plus empty weight of the copter w/cam. Does anyone have a motor recommendation for heavy lift copters within that thrust range? I also wish to be able to provide GPS coordinates of the copter at all times, altitude hold, and autohome when it senses low voltage. Last thing I want is to loose the copter or have it descend uncontrollably over people already in danger. Sooo, if any of you have recommendations as to the other components as well (Flight controller, ESC's, GPS, etc.) I welcome your input.