Why not just get a linear actualor? it would take your motor up and down with a push button and its simple. all you would half to do is mount the actualor to the motor and the frame and wire it up.
http://cgi.ebay.com/New-Linear-Actua...QQcmdZViewItem
I have used the one i linked to you. I wired it up at 12 volts and it worked like a charm. All you half to do is reverse the wires to make it go in the other direction. You can buy buttons that make it go up and down with one switch.