I think this will work...a relay version of an H-bridge. The variation from your original request is that the "direction" is started or changed with a two position DPDT toggle switch. Flipping the direction switch during transit will reverse direction of the motor.
Lance,
You are basically wanting the same circuit that older less sophisticated automotive power windows use. The diagram at the link below is a very straight forward schematic of that circuit, without the limit switches, which can easily be installed in both the "up wire" and "down wire". It uses a coupla standard automotive relays that can be purchased at any auto store.
You can view that diagram here... **broken link removed**
Lance,
You are basically looking for the same circuit as the older, less sophisticated setup for an automobile power window setup. This link shows that (easy to follow) circuit without the limit switches which, of course, would be placed in the "up wire" and "down wire". All that is required is the switch, a coupla automotive 5 pin automotive relays and your limit switches. **broken link removed**