So 54IR-AS and 54IR-ZE...
it's the same camera, the only difference is lens here.
54IR-AS have fixed lens - so you have choose at purchase that You want 2.8mm (very wide 112 degree horizontal) or 3.6mm (more normal 88 degree horizontal).
In case 54IR-ZE you have varifocal lens - where You can change zoom level between 112 and 47 degree horizontal at installation..
54IR-AS is little cheaper and brighter, 54IR-ZE is more universal.