need sound processor advice 2000 bmw

I am interested in sound processor advice:  I am integrating 2 seperate amps into my factory in-dash stereo in my 2000 BMW 5-series.  I have one ADS amp for the sub(s) and one Ad-Com amp for the rest.

I am planning on keeping the factory in-dash radio, and I want one aux. input for my satellite reciever.  The Ad-Com amp came with a pre-sound processor, but I am not familiar with the brand and I don't know if that will handle all four channels, along with an amp channel.

Does anyone here have advice on the best (cost not an issue) option to meet the needs I set above?  I had a friend suggest that I don't need a processor, 'cause the Ad-Com processor will take care of that.  He is suggesting that we add a switch for the aux input, to switch between the low-level satellite input and the low-level car stereo input.  The Ad-Com did come with the 5-pin XLR cables to run to the trunk.

Also, on a side note on the install:  The car takes 5 1/2" component speakers both front and rear.  What is the absolute best speaker on the market for that application?  The last stereo I built was over six years ago, and back then we were using Boston Pros, which were excellent, but things have changed so much.  I have two 10" boston pro subs saved for this car, but I may only use one if space is an issue.  If anyone could suggest the best components, I would appreciate it.

Thanks

Thank you for the info.  I have been checking into the REQ5, but since I have been out of audio for awhile, I wasn't sure if that would serve my exact purpose.

Regarding those speakers, I have never heard of that brand.  Where can I get them at a competitive price?  Are they available online?

I have been looking closer at the new Bostons, and the Focal brand components.  I am just looking for the best quality sound, not SPL, and price is (almost) no object when it comes to speakers.  I don't want to spend $1500 a pair, but $700/pair would be worth it if they are worth the $$.  I am not looking to be in competition or anything, just a picky car lover, and I would like to blow people away with quality sound when they ride in my car.