I think I read that you are using 1 component set and 1 subwoofer right? If so all you really need is the monoblock for your sub, and a 2 channel for the front unless you want to power the tweeters with the front side of the 4 channel and the mid on the rear. I run an amp on my tweeters, 1 on my midrange, 1 on my midbass, and 1 on my sub. I do all of this for a reason but if you are using a factory head unit with line out converter then the 2 channel and the mono will work just fine. If you have anymore questions just pm me and I'll do all I can to help you out.
Well guys I figured it was time for an update...Got the sub and my amp in last week, it sounded okay but now what I expected. It sounded like there was too much bass trying to go too my front speakers so I could hear a lot of distortion. Well today I had some time so I installed my CDT 6 1/2" speakers and tweeters. They didn't exactly fit the mount my Grand Prix has so some modifications had to be made for them to fit.
All in all I think it sounds 50 times better today than it did with just the sub installed. I have yet to install my speaker amp so right now they are just running off the factory headunit until probably tomorrow.
Next in line will be a headunit replacement and some 6x9's for the rear speakers. Have the headunit mounting stuff arriving Monday so I just have to find one I like!
Probably the best bang for the buck head unit out right now is the Pioneer 7800 or whatever the newest model is in that line. It has a true 4 volt out, time correction, built in eq, lots of nice features. If you don't mind getting an older unit look for a Alpine CDA-7998. They don't make them anymore and haven't for a few years but it the best cd player they have ever made. It does not have built in power though.
I know a guy that has an Image Dynamics IDMAX 12" for about $175 shipped. PM me and let me know if you want it. It is a $500 woofer. I actually use one myself. This thing plays LOW. It's -3db downpoint is at 10hz where most others are around 25-30. It is defintealy a sq woofer but man that thing can get loud.