I had a 2 set of the clarion plates in my previous92sport, I thought they sounded great! But I just installed the MB Quart 5.25 components all around in the 92 sport I just bought a month ago. What a superb sound! But I think unless your looking for a high price system the clarion pro audio plates are the way to go! For a 100 bucks a set(on sale at cruchfeild) you can't go wrong! I know I paid over 250 (per set) for my MB Quart componets.
Also in my opinion 93Eddiebauer, if you mounted your tweeters on the same plates as the woofers you have the same basic set up as the as the clarion pro audio plates!
I mounted my tweets above the power lock buttons on the door panels in the front, and in the back they are mounted on the top of the trim panels around the windows, then I angled them till I got the sound I was looking for.
Punkchild, If you go with a sub in the back you will need an amp for that. I think you would be happy with a plate speaker like the clarions, but I would definetly go with a decent4 channel amp to run your speakers, it won't have to be to high powered if you go with the clarions because there only rated for a max of 35 watts RMS with peaks of around a 100 watts. If you don't go with the sub, then I would consider a decent 3way speaker for the fronts and a set of 2 ways in back. I myself would still add a decent 4 channel amp to that set up also.
Thats my opinion,
Fresh