If you have followed the programming steps and it does not receive signal, then it is the antenna. But typically when you disconnect power from an aftermarket alarm system, you need to reprogram the remotes. I don't deal with Viper at the moment, but Visions should be able to get you parts. Unfortunately for you, the closest one to you is Port Coquitlam, or Langley, depending on which way you drive more.
As for OEM Alarm, in theory it should work. But if the remote requires programming or something along those lines, it may be more difficult to figure out than an after market system, as I'm sure less people are doing it. Hopefully it runs on a dip switch or similar, so it doesn't need programming. Just find out where every wire is going to, and write it all down. Like Yellow with red stripe from alarm, goes to white with blue stripe by drivers kick panel. You will need to trace every wire, unless the OEM alarm brain has a wiring diagram on it, then it would be a bit easier.
