A passport is not just for jet set models on the way to Paris, passports are also good for a model or actor to have for certain jobs that requrie ID. Such as background work or any work on TV or Films.
You can bring your photo ID, STATE ID, AND an original birth certificate, no copies.
To me the Passport is the easier choice.
You MUST bring ID when you are shooting background work or any work on TV Shows or Films and commercials, because you will need to fill out of a talent voucher and you will need these items.