If you're interested in going down the customization and wireless route, you might want to check out SimpliSafe, a self-install home security system that lets you place the sensors anywhere you feel needs protection most. The best part, you can take it with you whenever you move to your new home.
SimpliSafe incorporates wireless technology into every aspect of the security system - from the keypad, remote, and motion sensors - they all have a main connection to the base station, which manages to send an ear-blistering 85db alarm siren and contacts the service's call center to send out the police if you don't disable the alarm on your keychain.
We imagine all of this wireless tech will probably use up many batteries given the number of devices, but if that's fine with you, it'll be a great investment given the fact that you can save on installation costs and take it with you whenever you wish.
Update: Review of the SimpliSafe system available now here.