I second everything that ULTM8Z said about the Advanced Key system.
I have one in my 69 Camaro with the RFID, etc. It works great and is simple to understand. Its no more difficult to hook up than a typical remote starter (which it can actually be used as if you get the card/remote with buttons). I have an LS motor with the GM controller in it as well as an American Autowire harness. Its also tied into the door locks with no issues.
Here is a quick video of a start/shut down
https://www.youtube.com/watch?v=SxPWWD_AoU8