Dont forget this ignition uses a VATS key. It has a resistor built into it that prevents the car rfom starting if the reisitance is wrong.
I know this does not directly answer your question. As far as I know, no one has had much luck installing an aftermarket remote starter AND keep all the functionality of the factory key fob with all its available programming.
That might be why GM is making remote starters available in late 2003/early 2004 as an option on some of these cars.