2003 nissan altima R.S

I am going to put a valet remote start/ keyless entry system in a 2003 nissan altima. I was wondering what kind of bypass module am I going to need? I was also wondering about the factory keyless entry system. Do I just leave this intact or disconect it and use the valet keyless entry? I beleive all that this car has is just a factory keyless system and no factory alarm.  All help is appreciated. Thank you.

youll need a 556u or similar bypass.  factory keyless will work while the car is running, but its almost too easy not to add keyless.  brown and pink wires that  are next to eachother at the bcm next to the fuse box will unlock and lock the doors with - triggers.