hey mongoose is ok but like you ive heard alot of complaints... my personal recommendation is to go with a viper system. i had 1 in my last car and its the only alarm system i've ever liked. most other brands ive had experience with seemed cheaper and when installing them they didnt seem to have the same quality as the viper system. currently a viper system (top of the line) will be out of ur budget but there are still plenty of older models for sale that are in my opinion better then the current offerings from other brands, we currently have one on the shelf at work thats going on sale for 400 this saturday(im hoping no one buys it cause then i might get it cheaper) its got three point immobilization 6 channel remote (1 for lock 1 for unlock 1 for panic 1 for silence and 2 for wat ever you want eg remote start/boot release) it also has a sonar like system so it knows if someone smashes your window. current rrp for this system is (approx) 600 bucks.
hope my little spiel was helpful to some degree, and good luck with choosing a good system and ultimately like beeza said the quality of an alarm is 90% in the install anyway...