I am looking to completely remake my car's stereo system, and it seems like I have all the speakers I need. I will be buying two pairs of 300 watt JBL 6x9 inch speakers (http://www.amazon.com/gp/product/B003KN2TGM/ref=gno_cart_title_2) one subwoofer 250 watt bazooka tube (http://www.amazon.com/gp/product/B0017JHUG0/ref=gno_cart_title_4) and a pair of 180 watt one inch tweeters (http://www.amazon.com/gp/product/B000P0PF9Q/ref=gno_cart_title_1). so I am buying 7 total speakers. My questions are as follows

1) What amp should I buy if I want to hook everything up to it? There is no way I can buy a seven channel amp.

2) Are buying the tweeters even worth it? and would I need to hook both the tweeters up to an amp?

3) If i am buying a 300 watt pair of speakers, are they going to be 300 watts total? or are they going to be 300 watts each?

4) Also, THE AMPLIFIER. I dont know anything about the amplifier. This is the one I am looking at, (http://www.amazon.com/gp/product/B001AO4NUI/ref=gno_cart_title_3) but would that be able to cover my whole speaker system? or should i forget about buying the tweeters and just buy that four channel amp for the 6x9 speakers, and a mono amp for my subwoofer?

I am lost my friends, and need guidance. I cant find any online resources that explain this all in English. I want to redo my car stereo system, but I don't want to mess it up. I am mainly confused about the amplifier. For other information, I am getting this professionally done, I am just providing the parts, (amplifier, speakers, subwoffer, and tweeters) and they are providing the wiring and setup and mounting and all that. So if somebody could reply to this and give me some more information on what i need, or any other advice, please reply. I am LOST.