Active job

Need security help

WantING to get an alarm system installed the most trust worthy an good quality alarm system but also the cheapest I don't want to be on a contract or my house be monitored. I just want an alarm system that's loud an will go off if house is broken into so that neighbours can hear I just want to pay a one off payment. I also would like an alarm system with the most motion sensors. I DON'T NEED a touch screen key pad or remote or smoke detector or camera/video camera. I dont have a landline but i do have broadband if that helps. Also want a straight forward alarm system that's easy to operate. I live in a three bedroom house as well if that helps it's pretty standard an not big at all.