Seaworthy package or packing as your requirements.
DLC or as you pointed port
There are a variety of impeller castings and the common impeller casting include the impeller of the steam turbine made of medium-carbon steel, impeller shell, impeller of multi-level pump made of grey iron, impeller of the centrifugal pump, impeller of the electric submersible pump and stainless steel impeller.
OEM and ODM is welcomed
Die casting: Aluminum or alloy A360, A380, A390, ADC12,ADC10,ALSI09 etc.