I installed one on my '98. They make remote starters that are specifically made to work with your original remote. The trigger hooks into the door-locks and you can program it, for instance, to start if you hit unlock twice. Mine is a Bulldog, but I don't remember the model #. It works great.
A couple of tips, I know for sure that your 98 has the PATS key system, and the 96 may or may not. Make sure to get the transponder bypass kit to go along with the remote starter. If you do a search on here, you will find a LOT of info on that. Also, the GEM is programmed to not be able to unlock or lock the doors with the remote with the engine running. I also found a thread on here outlining how to install a relay that opens the signal circuit to the GEM when the remote starter is powered and essentially tricks the GEM into thinking the car isn't running. Then your remote will still work when the remote starter is running the car.
Sorry I don't have links to these threads, but if you do a search, I'm sure you will find a lot of information on all of this.
