Car Audio Central - Ultimate Car Audio Forum and Community

I'm new to the forum and a bit to car audio. I have a 2003 Mitsubishi Eclipse so needless to say the interior is tight. I'm just looking up upgrade my stock speakers. 6.5" in the front and 6"x9" in the back. I was going to buy a 4 channel 360W amp to power everything. I was going to run all new wiring from amp to the speakers. I have a list of what I'm looking to get from Best Buy, I have $80 in certificates, that I am going to include in this post. I'm looking for a basic Bluetooth head unit, nothing too fancy and I'm probably not going to add a sub enclosure either. If I decide I want to later I'll buy another amp for that. I'm looking for advice on what I'm getting for the price I'm paying. Going through BestBuy limits me I know but I'm not looking for anything crazy. Just nice clean sound with a little loudness. Here are my list of equipment:

Head Unit: Kenwood KDC-BT318Uhttp://www.bestbuy.com/site/kenwood-cd- ... 0300050000

Front Speakers: Alpine SPS-610Chttp://www.bestbuy.com/site/alpine-6-1- ... 3000050011

Rear Speakers: Pioneer TS-A6965Rhttp://www.bestbuy.com/site/pioneer-6-x ... cat0300000

Amp: Pioneer GMA6604http://www.bestbuy.com/site/pioneer-360 ... cat0302004

Questions I have about the installation.

1. Do my speakers and amp make sense - Could I do better for the price?
2. Connecting the wiring harness to the radio do I need to hook up the wires for the speakers seeing that I'm going to run new wiring from the amp to the speakers?
3. Is 12 gauge wire the gauge of wire you'd use?
4. Is there anything I'm overlooking or missing for my installation?