C.M.
Storm doors. Install impact doors instead. It is an added expense but it has been completely worth it for us. Besides the added security, for small storms, there is no need for additional hurricane shutters on those windows. You may also get a break on your homeowner's insurance (we did, but all the windows were changed).
Make sure you find the storm doors have top and bottom locking pins in addition to the dead bolt. That really secures the door.
We also have a security system and I can tell you that I sleep much more soundly knowing it's a pain to break into the house and that if, heaven forbid, someone break in again, the whole neighborhood would wake up to our alarm!!!
Best of luck!