OpenALPR works with virtually any IP camera. Here is a list of cameras that customers have reported success using:
Hikvision DS-2CD4A26FWD-IZH8 (You do not need the "/P" model):
ESG-IPBN2V4-Z - 2MP 4.7-47MM LONG RANGE BULLET
ESG-IPBP2V6-Z - 2MP LONG RANGE 6.5-143mm CAM
Depending on the distance to the vehicles, you may require an external IR illuminator to provide sufficient lighting for night capture.