I've done avital and compustar kits in the past. When I did the remote start on the wife's stratus (now, sebring) i used the OEM add-on kit; literally was a plug-n-play affair, and works perfectly. Sadly that kid is long discontinued, and I was lucky recently to find a new SKIM module part so as to transplant it from the Stratus to the Sebring.I had an old Avital 4103L around that I was going to use on my 1996 Chevy truck before the torque converter gave out, you might want to look around and see if something newer has better features. I used the same model on my 04 Sunfire for a few years without issues until the motor went on that. I haven't got a Security bypass on it yet as I live in the middle of nowhere, might put one in next year.
The parking lights and door lock feature work but I haven't been able to get door unlock to work with the correct resistor but I have a wiring diagram and will try with a relay direct to the door lock solenoid and skip the resistor and that isn't a big deal as I have relays around. I did post a question here about the door unlock issue and someone had the same result with the resistor. You can find wiring instructions at bulldogsecurity.com or the12volt.com
I heard the factory add on kit had bad range and a nephew had a KK and the remote start on it just quit working according to him and he never asked me to look at it.
I would avoid bulldog remote start as I have problems with those in the past but companies that are part of DEI are really good