OpenALPR works with virtually any IP camera.  Here is a list of cameras that customers have reported success using:
 
Vivotek IP816A-LPC-v2:
 
Hikvision DS-2CD4A26FWD-IZH8 (You do not need the "/P" model):
 
Axis Q1700-LE:
https://www.axis.com/products/axis-q1700-le
 
Eclipse
https://www.eclipsesurveillance.com/
Contact: joey@eclipsecctv.com
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.