I want to add a power button on my dash. Which can i use?

What kinda button do i have to use to add a auxiliary power button to my dash? I went to radio shack and i really couldnt tell the difference. I already ran my wires to the onboard button. Do i need a SPST, momentary, or what??? Also is there any kinda power requirement for the button. The ones at radio shack were rated at only 3v

Momentary, no power requirements since the AMP is too low.

Thanks! On my way to radio shack now.