I have a model from www.autocommand.com
installed on my 94. I did it myself and I'm not super handy by any means. It wasn't too hard, just find the correct color wire. Fishing the power wire through to the battery was the biggest pain. I ended up drilling a hole through the firewall to do it. Do that at your own risk.
Mine also has the key with the resistor in it. For that you need their security module, that costs around $25. You just test the resitance of your key and then dial that resitance into the module, so that was easy too.
I did it in steps, first the starter so I could be sure I hooked that up correctly, and then the security module. Until you have the security module installed, when you remote start, your security light will come on until you insert the key, then it will start up without turning. That was enough for testing purposes anyway.