I got an E-class Alpine. No I don't have an amp (yet). I was also thinking of getting an equalizer, what would you recommend? The Kenwoods are 500W, Kickers I don't know. Honestly, this is my first time working on sound systems on cars, it's new for me.
Most head units come with equalizers, although I dont know how they stack up against independent equalizers. Assuming your talking about the rated speaker wattage for your speakers when you mention your kenwoods and kickers, there is one important thing to know: Its a [censored] measurement. When you see on the box of speakers a number that says something like "800 watt speakers", that is referring to the MAX wattage that a speaker can get before blowing up a split second later. It means that that wattage is the wattage it can handle at the MAX, the wattage that it will play, but in fact break at the fastest. Pointless right? When it comes to measuring how much a speaker can handle, you want to look at the watts RMS, which stands for root mean square. Another name for this is continuous wattage. This is the wattage at which the speaker can handle continuously without degrading at an unnaturally fast rate. Many times they wont give you this number on the box, but on the back of the speaker with a sticker instead, or somewhere inside of the box. You will need an enclosure (box, in this case a sub box) for your sub, or else there is no point in having it, they don't sound like subs without being in enclosures.
Another thing to mention is wiring. Crap wiring can and often times will, make your equipment sound worse. Good wiring can, and often times will, make it sound better, to a point. If you have any questions on that let me know and I can explain. I will tell you one thing though, don't buy Monster brand wiring. Its usually more expensive the same as most other good wiring you can buy.
EDIT:I read up on independent equalizers and it looks like one would be overkill for your system.
EDIT: I was wrong about your sub not sounding like a sub if its not in an enclosure, however due to things with pressure, I've never heard of a sub that hasn't sounded better an an enclosure.