Upgrading stereo, need some advice

I just got my new headunit (p860mp) yesterday and I'm very pleased with it. I can't believe how great of an improvement it was from my old cheap low-end pioneer that i got from wal*mart. so now i'm in the process of upgrading my door speakers and possibly my rear speakers. i've been doing some research on speakers and this must be the hardest thing in car audio (from my experience) is finding certain speakers. i really want to keep my rears. I personally think it's nicer to have words coming from behind.

right now i have some cheap pioneers that came with the old hu so i'm pretty sure anything would sound 10x better than those. which of the following would be my best option?

1- replace front & rear speakers and run them off a 4-channel amp

I'm basically going for a SQL setup, but i'm slowly upgrading piece by piece every so often since I'm poor. haha. but anyways, i want something that will sound clean and crisp, and can be heard cleanly/clearly over the bass. the subs are 2 CVR's getting 787wrms off a jbl amp. plus, my rears are opened so they're noticeable inside  the trunk, instead of being closed. the bass from the trunk pushes them when they're off, and a few people told me that I need to box them so they won't be visible in the trunk. is this true? I dont wanna get some good rear speakers and you can't hear the mids or anything because of the bass from the trunk. I mainly use the rears just for the words/highs anyways. so i'm thinking keeping my pioneers and run them off a deck would be my best bet, but I want a second opinion on the pros.

After giving me my best option from above, what would be some good speakers and an amp? money isn't an issue right now, but I don't want to spend at least over $400, unless I have to. the car is a '97 saturn sc1, and both front and rears are 6.5". Also, I'm not sure what size depth it is for the doors, so I don't really want to get speakers that are too big that I have to do some custom work, because I'm not skilled when it comes to that. So would coaxils be my best route instead of components? I also noticed the CDT brand is pretty popular, as well as MB Quart, but I need some opinions from some pros on this forum.

lastly, my lights barely dim with the power I got now, if the volume is up a good bit, you can see the lights "blink" when the bass hits, but it's not noticeable, unless you really stare at it, if that makes any sense. If I had another amp for the speakers, will I have major problems? If so, can someone point me out to a good battery and alternator? I've read a couple times about people having problems with their alternator cause it wont charge unless past a certain RPM, which I don't really know what that means, but I don't want the same problem, I'm willing to spend a good amount of money for a good battery & alternator that won't let me down.

Sorry if it's so long, or hard to understand, I just need some help before I go making my own decisions.

Thanks.

leave the rear deck alone in fact take them out. and put all your focus on your front staging. thats where your stage is and sq comes in. i take it you want to use the factory cut outs in the door. so what you need to do is find mids with great off axis response. there are a good hand full of great mids out there some of them are even co-axil. but it,s what you  prefer co-axils or seperates. i like seperates cause i cant put the tweeter where I think sounds the best. weather it be ontop of the mid or 2 feet away. im a fan of polk. dbs for the family car and momo for my ride. but i know there is better and worse out there.. so what i would do is get the mids you want and get the amp thats match or close to the rms rating. get a four channel amp so you can power both front and rear off it. (and you dont need to use all four channels but it,s there if you need it)i personally never use deck power.  amps make a difference in sq too. and theres sound deadening to make your doors from resonating.    if you want to keep the rear speaks use some sort of baffle on the rears to keep the subs from "pushing" those. but put most youre attention up front.      but all in all i would vote for your # 1 option. if this helps. sorry for the long post.             thats all i have to say about that.

Thank you both for helping. Yeah I planned on deadening the doors as well as the trunk and trunk lid as soon as I get the chance. I like those Boston Acoustics link you sent, but I only saw the 6", would that still fit in the 6.5" inch hole? If they'll fit, I might go with those and a 2-channel amp, and just keep my pioneers off the deck, and get those baffel things you sent me as well for the rears.

Thanks again for the replys.

So are you saying if I amp my rears, I should get Boston Acoustics all the way around? If that would be the best bet, then I'll go with that. I found a set of BA on ebay new in box for like $100 including s&h, from a online store.

Well I would look locally but the only places around here sell low end Pioneer speakers and the crap at wal*mart which is out of the question, since I'm looking to upgrade to something better.

Truthfully I really didn't want to use any speakers on the deck, but I figured since I want more sound up front, and little in the back just to have the "extra" sound and for the people in the backseat, that option 2 would be good enough, but after thinking about it, and then reading your post, I agree having 2 sets of the same speakers for front and rear amped off a 4-channel amp would be pretty nice, and I would be very pleased with it. So, that's my plan as of now. But if I can't find 2 sets of the same Bostons, what are another "just as good" brand as those Bostons, or better? I heard some good reviews about the CDT coaxils, and by looking at your sig you own some CDT equipment. Would those be "just as good"?

If you or anyone could post some good speaker brands I can look into, as well as a link (if possible) I'd appreciate it. And some good 4-channel amps to look into, and a link as well (if possible), I'd appreciate that, too.

Thanks.