05 mustang audio

Hello all i have an opportunity to get some audio equipment from kicked for decent...well i guess cheap compared to their sticker (how i can of course i cant reveal) and im wondering about the best options in the 05 mustang. I read on a previous post some time ago about the idea of putting mid bass drivers in place of the 8" subwoofers and remember the dilemma of someone thinking that the subwoofer enclosure shared the same airspace as the 5x7 in the doors, and needing to seal this off. Someone else mentioned that they thought it was a sealed enclosure so it wouldnt be an issue, does anyone know which one of these is true? also, would it be feasible to have a 5 1/4 kicker component set (specifically the 09QS602) AND a mid bass driver in the front doors? i do also remember someone saying that you dont want the frequencies to overlap which im sure would happen if i were to use this kind of a set up with components that have a 5 1/2 woofer and 30mm tweeters + a mid base driver. Are there any component sets out there that inlcude a midbass, a woofer the size of either 5 1/4 and a tweeter? or would i be better off getting just a midbass and a tweeter? Also for an amp for these options. If i could do all 3 speakers in the door, how well would a 5 channel amp work on the component set up front, the midbass drivers, and the rears. Is it possible to run the 2 midbass drivers off of one channel on an amp? Or does that result in a ridiculous impedance that would result in a blown amp? The amp im looking at if this would work is a 10ZX7005 that delivers 85 watts to 4 channels and 420 in the 5th channel. If the set up with 3 speakers in each door up front would not work, what would be the best option for rears? just scratch them all together and use a 4 channel up front for the midbass and tweeters? or should i get something for feel sound and just leave them un amped? for the subs im looking at using a 10IX5001 which delivers 500 RMS to one channel at 2 Ohms to be used on a 12" L7 enclosure. Last question, whats the best way to handle this power? a 2nd battery? if so any ideas on where it could go, or a cap even?

2) i know that you need the channels to match whatever speaker set up you get but what im asking is how many channels does a 3 way component set like a midbass driver, woofer and tweeter need? Do they only need 1 crossover or do the come with 2? 4) i know that component sets come with crossover so if i were to just get the component sets in the front and some rear w/e for fill sound i only need a 4 channel amp, but the question was more asking do i need a 6 channel amp or some other alternative to do 3 way component in the front and w/e in the back i need to do some research and figure out how many amps my alt is to figure out the best way of powering. 1) on this one, does that mean you dont think its important for the midrange woofer and the 5 1/2 or 6 1/2 woofer (w/e i can get the right adapter plate) to have seperate aircavities? i though for sure they shouldnt share.