Computstar, love it, easy to install and its a 2way so i know if the car is locked or unlocked, bumped, set off, door open, ect. DEI makes a good alarm as well, viper, python, or what ever name they are using now.
I can install it if you like. read up on extra sensors too, glass break is a nice one to have, tilt if you are worried about the wheels, even a proximity sensor can be used very well to ward off people before they get in the car.