Any place along the NJ Metro stations should have longer term parking. There's information, phone numbers, and line maps at http://www.njtransit.com . When we visited relatives in New Jersey a few years ago, we drove up to the MetroPark station. We only used hourly parking, but I'm sure they should have some long-term-ish parking. The train ride itself was about an hour-ish, and ended at Penn Station. But definitely call and ask first laugh

"You need me. You wouldn't be much of a hero without a villain. And you do love being the hero, don't you. The cheering children, the swooning women, you love it so much, it's made you my most reliable accomplice." -- Lex Luthor to Superman, Question Authority, Justice League Unlimited