i had infinity reference components in my old car and i loved the sound. they could play plenty loud and sounded good with only a cheap JVC head unit powering them. the main benefit of components is that you CAN seperate the highs and midrange. it's harder to set up right, but when you do, it's great. i had my tweeters in the corners of the dash pointing up at the windshield. the sound blended perfectly well (i'm no car audio expert, but i know what i like)
my suggestion, get some 6.5" components, don't worry about turning the midrange, the sound isn't directional enough to be noticable. don't worry about getting rear speakers. on my setup, i could barely tell the difference with them on or off. just put the money towards an amp or subs. it might be a bit different in a coupe though.
check out
http://www.ikesound.com they screwed up my order, but i eventually got my stuff and it's pretty cheap.