need amp suggestions

My brother have these Pioneer Premier® 12" Component Subwoofers with 1000 Watts Max. Power. He want to blow his trunk off he is needs to know what amp at what ohms will do the trick for these asubs. below are the details about subs.
400 Watts Nominal Power
4-Ohm Single Voice Coil (C) or Dual Voice Coil (DVC)

Need to know what it is either DVC or SVC, adn what impendance. After that i cna give you an idea for a good amp.