I'm not an expert either, and you don't say what you're willing to pay, but last time I bought car speakers I got a cheap couple of 6.5" pyle 2 ways with included crossovers and tweeters, similar to these
http://cgi.ebay.com/Pyle-PLDV6K-6-5-Two-Way-Component-Speaker-System_W0QQitemZ260303732347QQcmdZViewItem?hash=item260303732347&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1318
and stuck them in some cheap pine enclosures like these
http://cgi.ebay.com/TWO-6-CAR-AUDIO-SPEAKER-WOOFER-ENCLOSURE-BOXES_W0QQitemZ270289608100QQcmdZViewItem?hash=item270289608100&_trkparms=72%3A1205|39%3A1|66%3A2|65%3A12|240%3A1318&_trksid=p3286.c0.m14
I like em. I also already had a couple 4 inch 3 way speakers in the front that I got at wal mart. I think they "lightning" brand or whatever.
Car stereo manufacturers are the biggest bunch of slimy con artists in the world by the way. Never believe anything they say. And don't buy anything if they don't give you any specs.
Speaker watts should be given as RMS continuous, or RMS at least. Not PMPO, or maximum or any of that BS. And I'd try to check more than one source in any case.