I recommend any DEI product. That's Avital, Hornet, Viper, Clifford. Same factory different name. To keep your GM warranty golden you probably want to stick with a DEI certified installer. And 2 Way with pager. Anything without the pager is basically useless for todays smash and grab.
DEI passlock kit, DEI battery backup siren, DEI battery backup for brain, dual zone sensor etc etc.
There are other brands just that's what I have used since the 90's. I used to use there talking module but too many people mess with your car lol. Kids would hit my car with basketball to make it talk.