Need Some help wit system

Hey first off let me say i did search and i found some answers but not all... 

i know that this must sound stupid to people who know but im new to installing audio systems.....

Im looking to do a whole system replace everything... the HU is goin to be pioneer 940, Im goin to have 2 sets of MBQ component speakers, Powerin them is goin to be a PG 4 channel amp 800watts which is from my boys car, 2 JL 10w6v2, powering them is goin to be a RF 900 or 1000 watts, I have a BC so my lights wont dim, I also heard of something called magic 3 i think is this better the a BC??..Aslo with the component speakers that = only 2 speakers right after i use the crossover.. Im goin to hook them up to the 4 channel AMP sound right??? Even thou theres really 4 in the front ( 2 tweeters and 2 door speakers)

Know i do know some stuff about car audio with the install but not everthing...Can anyone please help me.

Thanks

Open the hood and check out your electrical system integrity.  Add up the fuse ratings on the amps and see if the alternator will handle that extra load.  An alt upgrade is in store if it won't.  Hold off on the cap until the system is installed completely without it.  You might be returning it for a refund.  Check out the battery ground cable and cable from alt to battery.  Clean connection points and upgrade wires if needed to handle current.  See this site for wiring requirements for that amperage.

Draw a diagram of your system and figure your wire and cable needs.  Bigger is better.  Figure out your sub enclosure requirements and start building the box.

You will have more specific questions as the install gets going.  Those kinds of questions are much easier to field and you'll get more responses.