If you're thinking of moving to a 2 man aerial filming operation, then this device simply adds more control for the camera operator to allow them to capture those special shots. The cost is just shy of €75 and is available here: http://mikrokopter.altigator.com/sony-lancctrl-camera-remote-control-p-40797.html
Here is a video of my friend G testing it out on his trusty Vortex-8 Octocopter, which I will hopefully be doing an article on soon. As you can see, the Sony cx740 is a really great camera for aerial video and has a superb 'balanced optical steadyshot' stabilisation system that really helps to get rid of vibration. Coupled with the LANC-Ctrl this is a great combination for filming with a multicopter.