If you are going to leave your stock headunit, say bye bye to bass! The best speakers for the bose system are...well the ones that came in it. Go to your dealer and get new ones.

All aftermarket speakers are gonna lack low end, they simply aren't made for that. For a good system you need 3 things: Low (subwoofer), mids (woofers), Highs (tweeters). Now as for the "bose" part, youe not gonna get the sound you want outta that system. My old car had a monsoon system and i completly ripped it out. Your bose amp should be a the rear by the tire. You will need a wiring diagram to splice the wires and delete the amp. Its not hard, just tedious. Next, you will need a head unit, I suggest one with 3 pre-amp outputs (front, rear, sub). Then the wiring harness will NOT be the bose system one unless the door chimes come out of the speakers. If they do you will need the bose system harness. Next will be what everyone has been saying: Speakers, subs, amps, FUN!

I am using a Soundgate to get rca outputs for an amp.

I know aftermarket speakers are lacking low end, this would be why I wanted the sub. I do however want to replace the speakers that don't work because they aren't going to be used for bass but sound. Replacement Bose speakers are much higher than aftermarkets which I can add in. Also you saying a system needs 3 things I have just been asking for recommendations for things which give all 3 things: Component speakers for the front (mid & high) and subs (low) the back door speakers don't need to be much special since most sound heard comes from in front of you not behind.

I know that even with replacing all of these I will not get the best quality without replacing the headunit, but as of right now I am not able to find a suitable replacement that I like. For the one I like when I find it will involve even more work as I would like to do a double din unit so I need to track down a dash piece in tan from one of the newer trucks. I just don't see a urgent need for that.

On another note I've worked with the Monsoon systems before in the Camaro I had. The stock speakers compliment well with a well set sub system. Monsoon was however just a rip off of the Bose systems. They were decent for a stock system though. Also the amp for the Blazers are located in the center console, which is also under my 6 CD changer.

Now I appreciate all the input but I'm not looking to do a complete system overhaul just something to help compliment everything else.

I do have a final question though, would using 6 gauge wire significantly affect the performance of an amp that recommends using 4 gauge wire if I'm not going to be using it a full volume all the time?

http://www.the12volt.com/info/recwirsz.asp
that is a 'rough' comparison of reccommended wire size/amp power. although 6 gauge isn't listed, it would be between 4 and 8 gauge. And We can't really tell you a correct answer if we don't know which amp you are going with.

Sorry, I completely forgot about Soundgate and Re-Q.

What about this. Its single din and absolutely amazing. I have it and love it. The only reason I am changing is because I want GPS and bluetooth.

I actually had that same headunit in the Camaro before I traded it. It was really good but I want to have the Nav/DVD unit now as well which is why I was saying it was going to be more of a pain because I need to find a dash bezel to work with the double din.

Also, sorry I forgot that I never mentioned amps. Really I have no clue what amp to get. I would like to get one that could push the subs I mentioned no problems. I've been looking at some and a lot of the ones I like all recommend 4 gauge wiring which is why I asked my earlier question. The amps I've looked at and like have been:
Kenwood KAC-9104D
Kenwood KAC-9105D
Kenwood KAC-8104D
Kenwood KAC-8105D
Rockford Fosgate Prime R500

Also keep in mind I would like to stay cheap, but If there is significant gain to be had then I would like to know if I should go with a more expensive one of those I listed. Other brands are also on that site, but I've not had any experience with them such as, Hifonics? If they are reliable then they have some amps that are cheaper that seem to be the same as those I've listed. I just picked mostly Kenwood and RF equipment as I know they are usually very reliable and I've also heard that the RF amps are underrated in terms of output.

Now, would I be safe with the 6 gauge wire with these amps if I'm not always running it at full volume or not? If not then I know the RF amp only recommends 8 gauge wire. Once again thanks for the help.