Most car speaker manufacturers are aware that mouting depth is an important design factor to consider. As a result, I think you will find a lot of speakers are built for mounting in tight spaces.
Around here we have several local car audio stores, (audio advice, boomers audio, car toys, ect) Each one is pretty much an authorized dealer for a different kind of speaker (none of them really carry the same speakers as best buy (pioneer, infinity, ect.) ) I'd suggest you find some similar places and go have a listen. Tell them you are just looking for some good quality speakers for your car and don't want a huge sub and amp and all that good stuff.
Keep in mind that if you are going to install the speakers yourself, even if you get the same size of speaker that is currently in your car there is a good chance that the mounting holes won't match up and you will have to drills some new ones or build some brackets. For this reason I just paid the extra cost for installation (plus in my case I was already having the amp, sub, head unit, ect. all installed, plus the sub box built so adding the speaker installation was not a big deal)
