I am looking to build my first quad copter as a fully autonomous GPS system. I was looking at the pixhawk systems and am liking that but would appreciate any advice as far as that and the whole project goes.... I need to buy everything from the frame up and need reccomendations. This is my first quad-copter build and willl be used mostly for surveillance but I also need to be able to program it to fly to a pre determined destination, land, and return home either on command or after a couple minute timer. I am not a complete rookie however as I have been an r/c hobbyist for years but this will be first fully autonomous set up.... Thank you in advance for any offers of help!