I'm a fan of Rockford Fosgate. If you check around ebay you can get all four speakers for under $200. Easily the best quality I've heard :P
Only problem is I also have a 98 coupe, 6 1/2's don't fit up front. I had to use my 5.25's, then I had to drill screws into the door so they'd fit. The way they put the factory speakers in is utter crap.

 

6.5's will fit if you cut out the housing behind the speaker. its really easy to do if you have a dremmel tool or if a friend does, or you can use an air saw. but yes you will still have to drive in new screws into new holes. and also using 3M strip caulk (same stuff that dynamat is made of) around the edge of the speaker helps to keep the speaker from rattleing against the door.

 

Not RF sadly. Largest 6 1/2's I've seen... My 5.25's are better anyway. And I had to cut the back out for the 5.25's to fit too... bah.

 

I dont know how much space there is, but the RF speakers are designed to play a little deeper, and are built a bit deeper accordingly. I know that on my friends car, he tried to put some RF speakers in, but they were too deep; they would stick out past the door panel...

 

hmmm.... well that sucks, i haven't had any experience with these, but this is the first time i have heard of any 6.5's not fitting even when the door panel is cut out. well at least you got somethin that fits and sounds good to you.