okay I would like to start off by saying I apologize if this is written in the wrong section I am not a car guru whatsoever so I didn't know wherelse to put this.

I have a 2001 ford expedition and I'm currently looking into buying 4 new speakers a sub and an amp. I am looking at an Infinity Kappa 682.9cf speakers with 300watts. I have no idea what sub amp or any other pieces I'll need. so my question is besides the speakers subs and amps what other pieces do I need before I take them into a shop to get it all hooked up?

please help!