Rudycob1

I'm in the process of wanting to upgrade/replace my Bose system as I need a more up to date set up for my Sl55 2003.
I would like to have a good sound system, Bluetooth, dab radio, phone, reverse camera, ipod connectivity, sat Nav, cd, etc.
So here is were I'm confused.
How many speakers and types are there. So far I think I have established that there are two speakers per door, rear speakers, centre speaker and sub woofer.

1) is this correct and if so what sizes, wattage and ohms are they?

2) if I replace the door speakers with component system, what do you recommend. I have been looking at a 3 way component by Focal.

3) amplifier to run new door/A pillar components. What do you think of Edge amps?

4) 12 or 13" sub woofer in passenger footwell with separate amp. Recommendations. Been looking at a 12" slim line.

5) what are the speakers in the back and centre speaker and can these be run from the same new amp (5 channel) or run from the new head unit direct? Will they need replacing.

6) how do I know what chargers to use for the amps?

7) read a lot about people mentioning remote base control, what does it connect to?

8) depending on the head unit ( double din touchscreen recommendations) will any of my steering controls work and what will I need to connect to the head unit. What functions will I loose?

9) anything else that I will need

I know that these questions have been on here before and that this is very lengthy but your advise will be greatly appreciated as I'm totally confused with trying to figure our what I need and how to do it.

Thanks in advance.