Hey Brett, the amp will depend on your budget. Read one of my posts on here. I listed some examples of the amps for your sub. The buzzing noise is from your rca cables being too close to the power wires or you have a bad ground cable. To fix it, make clean ground wire to car's chassis. Use shielded directional rca cable for the amps. In case you can't find the post, try RF/Kicker/JL/JBL/Audiobahn 4125HCT/2300HCT/MTX etc.
Hey Brett, you'll know soon enough if your rca cables are good. If you hear any engine/power noise in your speakers, it means you need to get shielded directional rca cable. Run the cables on the opposite sides of your car. If your battery is on your right, then rca on your left and vise versa. Audiobahn A4125HCT and 2300HCT are the only 2 models that's been tested. If you're looking at Kicker, try KX600.1, and KX1200.1 amps. RF also makes similar amps too, RF T10001BD.