Can I still file a FAA Domestic flight plan?

Yes! If you are filing a regular VFR, IFR, or non RVSM flight-level IFR flight plan that stays in US airspace, you can file using the FAA/Domestic flight plan. If you're planning to file for a GPS T-route or to fly a GPS approach at your destination, then you can still file using the FAA/Domestic flight plan.