OpenALPR works with virtually any IP camera.  Here is a list of cameras that customers have reported success using:
Vivotek IP816A-LPC-v2:


Axis Q1700-LE:



Eclipse
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.