I just bought a Pioneer 4400hd stereo for my truck with new Alpine Type S speakers (SPS-610s in front, SPS-510s in rear). They sound great but it just feels like it is missing something. I am going to buy an Alpine MRP F300 amp and I was wondering what amp install kit would be best? Do I need 8 gauge or can I go with 4? I currently don't have a subwoofer but I may buy another amp and a subwoofer in the future.