Okay, I'm still keen on the pneumatics idea, and I've managed to find a video showing the pneumatic system inside Flange:



It looks like a custom made ram, a solenoid and a CO2 catridge with a few connecting pipes and nothing else (please correct me if I am wrong); does anyone know where I could buy a ram and a solenoid capable of handling full pressure from a CO2 cartridge at full pressure?

Also I shall get those cheaper 1000 rpm motors. I'll be using a Sabretooth 2x5 ESC which I have; I'm 90% sure it will cope fine with 2 of them and I assume 4 would be okay too? Just wanted to check with you guys before I bought anything as you all know better than I do :P