Well, I'd say use the 'search' but this one is too easy. You alternator output should be in your Owners manual, or possibly on the inside of your driver side door. As for those amps the only one I would take for price/power/quality, would be the JBL. Just to let you know though, there is no JBL bp400.1, there is a 300.1 a 600.1 and a 1200.1, also a 180.2. I know the 300.1 needs 2 20 amp fuses, i figure it probably draws about 35 amps at it's maximum output. But for the JBL, I believe all there AMP specs are on the website.