Cadillac Catera 97 question

It seems that it's not easy to install a complete alarm with remote start and all the other features available today with this car. I did the search and only two posts came up with one of the posts sounding not so promising. The car has it's own alarm anti-theft system and uses a key with a chip imbedded. I don't exactly know which question to ask first. But like i said, I'm thinking of installing an aftermarket alarm/remote start system (with paging) to the car and was actually thinking of doing it myself. I realize that some kind of a bypass module is needed for most modern car, but checking on some bypass modules available, there is nothing compatible for use on this car. Before i go on installing or even have someone install a new car alarm/remote start system to the car, I hope someone with experience in the past on this car to give me an advice if i should just forget about it or go on with it. Thanks.

Since my car came with a keyless remote, is there anything i need to consider strongly before i install an aftermarket remote/keyless entry/remote starter/alarm system? I mean, i believe that i have to bypass the oem alarm system, but is there any important point that i have to be aware of that is specific to my car before i proceed. So far, Autopage 855 seems to be the most reasonable system to adapt because it has almost everything that i will need and the price is reasonable. Considering this alarm unit, are there anything that i need to pay attention to? I am thinking all of you gurus might have some input before i start with the project. This is going to be my first install, i have the patience since i have been doing most of the repairs of my car. I just want to upgrade the security of the car hence my interest in installing an aftermarket one. Thanks for any input and i know that i can always post here in case problems arises.