I'd bet that the aftermarket rotors are the problem. As Donnie said, OEM parts generally are the least trouble prone solution. If your ABS is getting whacky, then something was done to disturb the sensors. The hubs are still original, right??. Are your stops (such as they are) in a straight line, or are you pulling? This is not something to mess with, Your brakes are the only thing between you and other objects (cars, people, buildings, etc.) Get it squared away pronto...PLEASE..
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.