bigcamotruck

I have a base model 2000 4runner with no remote lock/unlock. I want to install an alarm. I checked on ebay and I can get a RS3200 with all the wiring harnesses (the 4runner has all the pertinent harnesses prewired, I checked the installation guide), what would happen if I installed it without the remote lock/unlock system installed? Would the alarm still arm when I close and lock the doors? On the flip side, would it disarm when I unlocked the doors with a key? How hard would it be to find and install the OEM remote lock/unlock system on a 4runner that is lacking it? I would like it to stay stock, and it seems like the cheapest route to go since I could do all the work myself, so that is why I ask.