DEI is a big manufacturer of alarms. Anything made by them would be good. Avital, Viper, to name a couple. I have an avital in my Legend. Remote start, trunk release, keyless entry. You can get an avital with keyless entry, shock sensor, etc. for $200 installed at Best Buy. It will only take a couple hours to install, plus you can go back to them if you have any problems. I wouldn't try installing it yourself unless your friend has experience.