When I was making my
actuated grill block for the Matrix, I was doing something similar. I needed to be able to reverse the door lock actuator I was using. I got the advice from dcb to use an h-bridge to control it. You should be able to use one for your setup.
If you aren't using any controller (I used an arduino) you'll need to add limit switches to the setup though. Door lock actuators are dumb. You give them power and they keep trying to go in our out until you disconnect the power. If you leave the power on them too long I'm sure they'd burn up. You'll have to add switches and relays to each end, so when it reaches the end of the throw it disconnects power.