For the door, make sure you are not using a hollow core door, and that you reinforce the frame, while also using an aftermarket strike/kickplate that has been developed for security, as that will make it much more difficult to just kick the door in. I would also looking at getting a core from a good company, not just some off the shelf part, because the better locks can be hard to find. Also, something that is more than just your normal pin and tumbler lock, like a dimple lock, can help. ABUS makes really good locks, and I would recommend looking at them. There's a few others too. You might want to look outside the residential core offerings they have into the commercial grade ones. (make sure to look for something as close to bump-proof and rake-proof as possible. Again, things like dimple locks will help here.) Same goes for the protection plates on the doors, so someone can't just card your door open or anything. No solution is going to stop a determined attacker forever, but doing these things will make it significantly harder to breach the door, and makes it more likely that someone maybe tries to kick it in once or twice and then leaves.