I am thinking about upgrading the stock CD stereo system in my 2000 F150. I would like to keep the exisiting CD unit and work on the actual speakers. I was trying to double the wattage and increase the bass. I have a regular car so I don't have a lot of room to work with. Can I still double wattage with the existing CD stereo. Any recommendation on what type of speakers. Do I need amps, equalizers, all that stuff. Any idea on pricing, where to buy, etc. I was looking to spend about $500 or less. Very much appreciated.