Can you purchase two of these together to open a double set of gates. If so will one remote be able to open both gates at once?

In order to use 2 single gate systems to operate a double gate you will need to have 2 complete single kits, batteries, and solar panels. These systems won't be able to communicate with each other in any way so a keypad will not be able to open both gates. You would need to push 2 separate buttons to open both gates and a zombielock would not be able to function on this system. The only way for a double gate to work in tandem with each other and the accessories would be to use a double gate kit and trench or under the driveway to connect the second arm to the dual control box.