[Al Skierkiewicz]

It is pretty easy to connect the two cylinders back to back with simple hardware, i.e. bolt and nut. then the actuator rods extend out in two opposite directions. You cannot drive both from the same valve however. With the two valves, you can drive them under software control to both actuate at the same time or you can wire both valves to a single Spike to turn them on at the same time.