Looks like a centrifugal blower (supercharger) to me! What brand is it? Vortech, Paxton or Procharger? From the looks of the intercooler I'm calling it a Vortech...
That will wake that car up for sure!
I have had good luck with metal polish...I'ved used Mothers as well as Adams and have had excellent results with both. I'm sure almost anything AG sells here will do the trick for you. It is indeed aluminum. The bracket, blower and intercooler are all aluminum.
Take your time and polish it up...Keep us posted with pics before, during and after! It should really clean up well and get extremely shiny. PIA to keep clean, but it will be worth it when you pop the hood.
How much boost (psi) are you going to run and is there anything else done to your car?