Do I need a fuel pump and regulator to use this tank?

Pump and regulator are sold separately. The tank itself is a container—you'll need to spec those components based on your fuel system pressure and flow requirements.

Will the polished finish stay shiny, or does it need protective coating?

Polished aluminum will oxidize over time, especially if the tank sits in weather. Many builders seal it with clear coat or store it indoors. It won't affect function, just appearance.

Does this tank mount with factory brackets or custom fab?

Mounting method is not confirmed—verify tank dimensions and your install location before ordering. You may need custom straps, brackets, or baffles depending on the application.