How to stop two DC motors simultaneously using limit switches
Due to the weight involved, I would look at using variable speed drives to allow smooth/controlled starting and stopping of the motors as well as speed control.
You could use AC or DC motor for this application with correct associated VSD (variable speed drive).
You could wire limit switches into the VSD start/stop logic as well as syncing the speed and preventing one pulling against the other using some hard-wired interlocks.
Some good examples of typical schematics can be found here:

http://www.moeller.net/en/support/wiring_manual.jsp

http://www.schneider-electric.com.co/documents/soporte/automtaizacion.pdf