Be careful, the door speakers are actualy 6x8 for the '02 model, adn not 6x9.
Some 6x9 will fit, but in my Sport they are two big.
As far as speaker brands go, anything after market will soundd better than what is factory supplied.
What kind of music do you listen to, and generally how loud? If you are going to stress the speakers, I would suggest getting something higher-end. If you are looking for a "BOSE" kind of sound you may want to look into Boston Acoustics or MB Quart. Most times though, you want get the proper power handling for these unless you go the lengths of installing aftermarket amplifiers.
As far as the subwoofer, anything that fits for an 8" enclosure should work just fine. I do not have a factory one installed, so I do not know the specs for it.
Can anyone provide the RMS power handling for the factory subwoofer?