Quad ESCs
Qty 4
Purchased from Rotor Geeks, and also available direct from www.spedix-rc.com. They required soldering to the pads on the ESC. That might be simpler, no heat shrink on the individual wires, but less forgiving.
The ESC on the original mozzie already had three wires attached. Those wires just needed to be soldered to the motor wires, and each of those connections were heatshrinked.
The quad ESCs don't need BEC. Without BEC they are quieter, smaller and lighter.