If you want just a bit more than the standard package, the Fox Guard Plus is your choice. It adds the detection of fire to your system, as well as the mini door/window sensors, a motion sensor, and a keyfob.
1 Lynx Touch 5210 All-In-One Keypad, Siren, Backup Battery, and Alarm System
1 Motion Sensors
3 Mini Door/Window Sensors
1 Smoke Detector
1 WiFi Communicator (subscription required)