A simple DJI Phantom will easily get to that altitude. Slight modifications would be required - possibly a different receiver and remote control to ensure the r

A simple DJI Phantom will easily get to that altitude. Slight modifications would be required - possibly a different receiver and remote control to ensure the range, and an FPV system (camera and transmitter on the copter, and a receiver with a screen or video goggles on the ground). Altogether easily done in under $1000. Control is real-time, just like any other flying model aircraft or multirotor. For flying at that altitude, I'd use FPV - meaning you'd fly using the camera image to pilot the copter viewed through a screen or even better, video goggles, as opposed to looking at the model from the ground. Be aware though that at this altitude, you're often in controlled airspace, which is troublesome for model aircraft in most cases.