Check out Viper Alarms. I didn't add it the remote start (it is available on my model - see sig), but mine was $299 installed. That gave me Remote entry (didn't have OEM RKE) and alarm. Remote start is "built in" so only a relay and wiring is needed. Comes with 2 OEM quality remotes and I haven't checked the range, but it worked easily from my office to my car (150 ft through the building).
Worth a look IMHO
